Neprilysin inhibitors

ABSTRACT

In one aspect, the invention relates to compounds having the formula: 
     
       
         
         
             
             
         
       
     
     where R 1 -R 6 , a, b, and X are as defined in the specification, or a pharmaceutically acceptable salt thereof. These compounds have neprilysin inhibition activity. In another aspect, the invention relates to pharmaceutical compositions comprising such compounds; methods of using such compounds; and processes and intermediates for preparing such compounds.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of U.S. Provisional Application No.61/423,180, filed on Dec. 15, 2010; the entire disclosure of which isincorporated herein by reference.

BACKGROUND OF THE INVENTION Field of the Invention

The present invention relates to novel compounds havingneprilysin-inhibition activity. The invention also relates topharmaceutical compositions comprising such compounds, processes andintermediates for preparing such compounds and methods of using suchcompounds to treat diseases such as hypertension, heart failure,pulmonary hypertension, and renal disease.

State of the Art

Neprilysin (neutral endopeptidase, EC 3.4.24.11) (NEP), is anendothelial membrane bound Zn²⁺ metallopeptidase found in many organsand tissues, including the brain, kidneys, lungs, gastrointestinaltract, heart, and the peripheral vasculature. NEP degrades andinactivates a number of endogenous peptides, such as enkephalins,circulating bradykinin, angiotensin peptides, and natriuretic peptides,the latter of which have several effects including, for example,vasodilation and natriuresis/diuresis, as well as inhibition of cardiachypertrophy and ventricular fibrosis. Thus, NEP plays an important rolein blood pressure homeostasis and cardiovascular health.

NEP inhibitors, such as thiorphan, candoxatril, and candoxatrilat, havebeen studied as potential therapeutics. Compounds that inhibit both NEPand angiotensin-I converting enzyme (ACE) are also known, and includeomapatrilat, gempatrilat, and sampatrilat. Referred to as vasopeptidaseinhibitors, this latter class of compounds is described in Robl et al.(1999) Exp. Opin. Ther. Patents 9(12): 1665-1677.

SUMMARY OF THE INVENTION

The present invention provides novel compounds that have been found topossess neprilysin (NEP) enzyme inhibition activity. Accordingly,compounds of the invention are expected to be useful and advantageous astherapeutic agents for treating conditions such as hypertension andheart failure.

One aspect of the invention relates to a compound of formula I:

where:

R¹ is selected from —OR⁷ and —NR⁸R⁹;

R² is H or —P(O)(OH)₂ or R² is taken together with R⁷ to form —CR¹⁸R¹⁹—or is taken together with R⁸ to form —C(O)—;

X is a —C₁₋₉heteroaryl;

R³ is absent or is selected from H; halo; —C₀₋₅alkylene-OH; —NH₂;—C₁₋₆alkyl; —CF₃; —C₃₋₇cycloalkyl; —C₀₋₂alkylene-O—C₁₋₆alkyl; —C(O)R²⁰;—C₀₋₁alkylene-COOR²¹; —C(O)NR²²R²³; —NHC(O)R²⁴; ═O; —NO₂; —C(CH₃)═N(OH);phenyl optionally substituted with one or two groups independentlyselected from halo, —OH, —CF₃, —OCH₃, —NHC(O)CH₃, and phenyl;naphthalenyl; pyridinyl; pyrazinyl; pyrazolyl optionally substitutedwith methyl; thiophenyl optionally substituted with methyl or halo;furanyl; and —CH₂-morpholinyl; and R³, when present, is attached to acarbon atom;

R⁴ is absent or is selected from H; —OH; —C₁₋₆alkyl;—C₁₋₂alkylene-COOR³⁵; —CH₂OC(O)CH(R³⁶)NH₂; —OCH₂OC(O)CH(R³⁶)NH₂;—OCH₂OC(O)CH₃; —CH₂OP(O)(OH)₂; —CH₂CH(OH)CH₂OH;—CH[CH(CH₃)₂]—NHC(O)O—C₁₋₆alkyl; pyridinyl; and phenyl or benzyloptionally substituted with one or more groups selected from halo,—COOR³⁵, —OCH₃, —OCF₃, and —SCF₃; and R⁴, when present, is attached to acarbon or nitrogen atom;

or R³ and R⁴ are taken together to form -phenylene-O—(CH₂)₁₋₃— or-phenylene-O—CH₂—CHOH—CH₂—;

a is 0 or 1; R⁵ is selected from halo, —CH₃, —CF₃, and —CN;

b is 0 or an integer from 1 to 3; each R⁶ is independently selected fromhalo, —OH, —CH₃, —OCH₃, and —CF₃;

R⁷ is selected from H, —C₁₋₈alkyl, —C₁₋₃alkylene-C₆₋₁₀aryl,—C₁₋₃alkylene-C₁₋₉heteroaryl, —C₃₋₇cycloalkyl, —[(CH₂)₂O]₁₋₃CH₃,—C₁₋₆alkylene-OC(O)R¹⁰, —C₁₋₆alkylene-NR¹²R¹³, —C₁₋₆alkylene-C(O)R³¹,—C₀₋₆alkylenemorpholinyl, —C₁₋₆alkylene-SO₂—C₁₋₆alkyl,

R¹⁰ is selected from —C₁₋₆alkyl, —O—C₁₋₆alkyl, —C₃₋₇cycloalkyl,—O—C₃₋₇cycloalkyl, phenyl, —O-phenyl, —NR¹²R¹³, —CH[CH(CH₃)₂]—NH₂,—CH[CH(CH₃)₂]—NHC(O)O—C₁₋₆alkyl, and —CH(NH₂)CH₂COOCH₃; and R¹² and R¹³are independently selected from H, —C₁₋₆alkyl, and benzyl; or R¹² andR¹³ are taken together as —(CH₂)₃₋₆—, —C(O)—(CH₂)₃—, or —(CH₂)₂O(CH₂)₂—;R³¹ is selected from —O—C₁₋₆alkyl, —O-benzyl, and —NR¹²R¹³; and R³² is—C₁₋₆alkyl or —C₀₋₆alkylene-C₆₋₁₀aryl;

R⁸ is selected from H, —OH, —OC(O)R¹⁴, —CH₂COOH, —O-benzyl, -pyridyl,and —OC(S)NR¹⁵R¹⁶; R¹⁴ is selected from H, —C₁₋₆alkyl, —C₆₋₁₀aryl,—OCH₂—C₆₋₁₀aryl, —CH₂O—C₆₋₁₀aryl, and —NR¹⁵R¹⁶; and R¹⁵ and R¹⁶ areindependently selected from H and —C₁₋₄alkyl;

R⁹ is selected from H, —C₁₋₆alkyl, and —C(O)—R¹⁷; and R¹⁷ is selectedfrom H, —C₁₋₆alkyl, —C₃₋₇cycloalkyl, —C₆₋₁₀aryl, and —C₁₋₉heteroaryl;

R¹⁸ and R¹⁹ are independently selected from H, —C₁₋₆alkyl, and—O—C₃₋₇cycloalkyl, or R¹⁸ and R¹⁹ are taken together to form ═O;

R²⁰ is selected from H and —C₁₋₆alkyl;

R²¹ and R³⁵ are independently selected from H, —C₁₋₆alkyl,—C₁₋₃alkylene-C₆₋₁₀aryl, —C₁₋₃alkylene-C₁₋₉heteroaryl, —C₃₋₇cycloalkyl,—[(CH₂)₂O]₁₋₃CH₃, —C₁₋₆alkylene-OC(O)R²⁵; —C₁₋₆alkylene-NR²⁷R²⁸,—C₁₋₆alkylene-C(O)R³³, —C₀₋₆alkylenemorpholinyl,—C₁₋₆alkylene-SO₂—C₁₋₆alkyl,

R²⁵ is selected from —C₁₋₆alkyl, —O—C₁₋₆alkyl, —C₃₋₇cycloalkyl,—O—C₃₋₇cycloalkyl, phenyl, —O-phenyl, —NR²⁷R²⁸, —CH[CH(CH₃)₂]—NH₂,—CH[CH(CH₃)₂]—NHC(O)O—C₁₋₆alkyl, and —CH(NH₂)CH₂COOCH₃; R²⁷ and R²⁸ areindependently selected from H, —C₁₋₆alkyl, and benzyl; or R²⁷ and R²⁸are taken together as —(CH₂)₃₋₆—, —C(O)—(CH₂)₃—, or —(CH₂)₂O(CH₂)₂—; R³³is selected from —O—C₁₋₆alkyl, —O-benzyl, and —NR²⁷R²⁸; and R³⁴ is—C₁₋₆alkyl or —C₀₋₆alkylene-C₆₋₁₀aryl;

R²² and R²³ are independently selected from H, —C₁₋₆alkyl, —CH₂COOH,—(CH₂)₂OH; —(CH₂)₂OCH₃, —(CH₂)₂SO₂NH₂, —(CH₂)₂N(CH₃)₂,—C₀₋₁-alkylene-C₃₋₇cycloalkyl, and —(CH₂)₂-imidazolyl; or R²² and R²³are taken together to form a saturated or partially unsaturated —C₃₋₅heterocycle optionally substituted with halo, —OH, —COOH, or —CONH₂; andoptionally containing an oxygen atom in the ring;

R²⁴ is selected from —C₁₋₆alkyl; —C₀₋₁alkylene-O—C₁₋₆alkyl; phenyloptionally substituted with halo or —OCH₃; and —C₁₋₉heteroaryl; and

R³⁶ is selected from H, —CH(CH₃)₂, phenyl, and benzyl;

where each alkyl group in R¹, R³, and R⁴ is optionally substituted with1 to 8 fluoro atoms; and;

where the methylene linker on the biphenyl is optionally substitutedwith one or two —C₁₋₆alkyl groups or cyclopropyl;

or a pharmaceutically acceptable salt thereof.

Another aspect of the invention relates to pharmaceutical compositionscomprising a pharmaceutically acceptable carrier and a compound of theinvention. Such compositions may optionally contain other therapeuticagents. Accordingly, in yet another aspect of the invention, apharmaceutical composition comprises a compound of the invention as thefirst therapeutic agent, one or more secondary therapeutic agent, and apharmaceutically acceptable carrier. Another aspect of the inventionrelates to a combination of active agents, comprising a compound of theinvention and a second therapeutic agent. The compound of the inventioncan be formulated together or separately from the additional agent(s).When formulated separately, a pharmaceutically acceptable carrier may beincluded with the additional agent(s). Thus, yet another aspect of theinvention relates to a combination of pharmaceutical compositions, thecombination comprising: a first pharmaceutical composition comprising acompound of the invention and a first pharmaceutically acceptablecarrier; and a second pharmaceutical composition comprising a secondtherapeutic agent and a second pharmaceutically acceptable carrier. Inanother aspect, the invention relates to a kit containing suchpharmaceutical compositions, for example where the first and secondpharmaceutical compositions are separate pharmaceutical compositions.

Compounds of the invention possess NEP enzyme inhibition activity, andare therefore expected to be useful as therapeutic agents for treatingpatients suffering from a disease or disorder that is treated byinhibiting the NEP enzyme or by increasing the levels of its peptidesubstrates. Thus, one aspect of the invention relates to a method oftreating patients suffering from a disease or disorder that is treatedby inhibiting the NEP enzyme, comprising administering to a patient atherapeutically effective amount of a compound of the invention. Anotheraspect of the invention relates to a method of treating hypertension,heart failure, or renal disease, comprising administering to a patient atherapeutically effective amount of a compound of the invention. Stillanother aspect of the invention relates to a method for inhibiting a NEPenzyme in a mammal comprising administering to the mammal, a NEPenzyme-inhibiting amount of a compound of the invention.

Since compounds of the invention possess NEP inhibition activity, theyare also useful as research tools. Accordingly, one aspect of theinvention relates to a method of using a compound of the invention as aresearch tool, the method comprising conducting a biological assay usinga compound of the invention. Compounds of the invention can also be usedto evaluate new chemical compounds. Thus another aspect of the inventionrelates to a method of evaluating a test compound in a biological assay,comprising: (a) conducting a biological assay with a test compound toprovide a first assay value; (b) conducting the biological assay with acompound of the invention to provide a second assay value; wherein step(a) is conducted either before, after or concurrently with step (b); and(c) comparing the first assay value from step (a) with the second assayvalue from step (b). Exemplary biological assays include a NEP enzymeinhibition assay. Still another aspect of the invention relates to amethod of studying a biological system or sample comprising a NEPenzyme, the method comprising: (a) contacting the biological system orsample with a compound of the invention; and (b) determining the effectscaused by the compound on the biological system or sample.

Yet another aspect of the invention relates to processes andintermediates useful for preparing compounds of the invention.Accordingly, another aspect of the invention relates to a process ofpreparing compounds of formula I, comprising the step of coupling acompound of formula 1 with a compound of formula 2:

to produce a compound of formula I; where P¹ is H or amino-protectinggroup selected from t-butoxycarbonyl, trityl, benzyloxycarbonyl,9-fluorenylmethoxycarbonyl, formyl, trimethylsilyl, andt-butyldimethylsilyl; and where the process further comprisesdeprotecting the compound of formula 1 when P¹ is an amino protectinggroup; and where R¹-R⁶, a, b, and X are as defined for formula I.Another aspect of the invention relates to a process of preparing apharmaceutically acceptable salt of a compound of formula I, comprisingcontacting a compound of formula I in free acid or base form with apharmaceutically acceptable base or acid. In other aspects, theinvention relates to products prepared by any of the processes describedherein, as well as novel intermediates used in such process. In oneaspect of the invention novel intermediates have formula 1, 6, 7, 8, or9, or a salt thereof, as defined herein.

Yet another aspect of the invention relates to the use of a compound offormula I or a pharmaceutically acceptable salt thereof, for themanufacture of a medicament, especially for the manufacture of amedicament useful for treating hypertension, heart failure, or renaldisease. Another aspect of the invention relates to use of a compound ofthe invention for inhibiting a NEP enzyme in a mammal. Still anotheraspect of the invention relates to the use of a compound of theinvention as a research tool. Other aspects and embodiments of theinvention are disclosed herein.

DETAILED DESCRIPTION OF THE INVENTION Definitions

When describing the compounds, compositions, methods and processes ofthe invention, the following terms have the following meanings unlessotherwise indicated. Additionally, as used herein, the singular forms“a,” “an,” and “the” include the corresponding plural forms unless thecontext of use clearly dictates otherwise. The terms “comprising”,“including,” and “having” are intended to be inclusive and mean thatthere may be additional elements other than the listed elements. Allnumbers expressing quantities of ingredients, properties such asmolecular weight, reaction conditions, and so forth used herein are tobe understood as being modified in all instances by the term “about,”unless otherwise indicated. Accordingly, the numbers set forth hereinare approximations that may vary depending upon the desired propertiessought to be obtained by the present invention. At least, and not as anattempt to limit the application of the doctrine of equivalents to thescope of the claims, each number should at least be construed in lightof the reported significant digits and by applying ordinary roundingtechniques.

The term “alkyl” means a monovalent saturated hydrocarbon group whichmay be linear or branched. Unless otherwise defined, such alkyl groupstypically contain from 1 to 10 carbon atoms and include, for example,—C₁₋₄alkyl, —C₁₋₅alkyl, —C₂₋₅alkyl, —C₁₋₆alkyl, —C₁₋₈alkyl, and—C₁₋₁₀alkyl. Representative alkyl groups include, by way of example,methyl, ethyl, n-propyl, isopropyl, n-butyl, s-butyl, isobutyl, t-butyl,n-pentyl, n-hexyl, n-heptyl, n-octyl, n-nonyl, n-decyl and the like.

When a specific number of carbon atoms is intended for a particular termused herein, the number of carbon atoms is shown preceding the term assubscript. For example, the term “—C₁₋₆alkyl” means an alkyl grouphaving from 1 to 6 carbon atoms, and the term “—C₃₋₇cycloalkyl” means acycloalkyl group having from 3 to 7 carbon atoms, respectively, wherethe carbon atoms are in any acceptable configuration.

The term “alkylene” means a divalent saturated hydrocarbon group thatmay be linear or branched. Unless otherwise defined, such alkylenegroups typically contain from 0 to 10 carbon atoms and include, forexample, —C₀₋₁alkylene-, —C₀₋₆alkylene-, —C₁₋₃alkylene-, and—C₁₋₆alkylene-. Representative alkylene groups include, by way ofexample, methylene, ethane-1,2-diyl (“ethylene”), propane-1,2-diyl,propane-1,3-diyl, butane-1,4-diyl, pentane-1,5-diyl and the like. It isunderstood that when the alkylene term include zero carbons such as—C₀₋₁alkylene-, such terms are intended to include the absence of carbonatoms, that is, the alkylene group is not present except for a covalentbond attaching the groups separated by the alkylene term.

The term “aryl” means a monovalent aromatic hydrocarbon having a singlering (i.e., phenyl) or one or more fused rings. Fused ring systemsinclude those that are fully unsaturated (e.g., naphthalene) as well asthose that are partially unsaturated (e.g.,1,2,3,4-tetrahydronaphthalene). Unless otherwise defined, such arylgroups typically contain from 6 to 10 carbon ring atoms and include, forexample, —C₆₋₁₀aryl. Representative aryl groups include, by way ofexample, phenyl and naphthalene-1-yl, naphthalene-2-yl, and the like.

The term “cycloalkyl” means a monovalent saturated carbocyclichydrocarbon group. Unless otherwise defined, such cycloalkyl groupstypically contain from 3 to 10 carbon atoms and include, for example,—C₃₋₅cycloalkyl, —C₃₋₆cycloalkyl and —C₃₋₇cycloalkyl. Representativecycloalkyl groups include, by way of example, cyclopropyl, cyclobutyl,cyclopentyl, cyclohexyl and the like.

The term “halo” means fluoro, chloro, bromo and iodo.

The term “heterocycle” is intended to include monovalent unsaturated(aromatic) heterocycles having a single ring or two fused rings as wellas monovalent saturated and partially unsaturated groups having a singlering or multiple condensed rings. The heterocycle ring can contain from3 to 15 total ring atoms, of which 1 to 14 are ring carbon atoms, and 1to 4 are ring heteroatoms selected from nitrogen, oxygen or sulfur.Typically, however, the heterocycle ring contains from 3 to 10 totalring atoms, of which 1 to 9 are ring carbon atoms, and 1 to 4 are ringheteroatoms. The point of attachment is at any available carbon ornitrogen ring atom. Exemplary heterocycles include, for example,—C₁₋₇heterocycle, —C₃₋₅heterocycle, —C₂₋₆heterocycle, —C₃₋₁₂heterocycle,—C₅₋₉heterocycle, —C₁₋₉heterocycle, —C₁₋₁₁heterocycle, and—C₁₋₁₄heterocyle.

Monovalent unsaturated heterocycles are also commonly referred to as“heteroaryl” groups. Unless otherwise defined, heteroaryl groupstypically contain from 5 to 10 total ring atoms, of which 1 to 9 arering carbon atoms, and 1 to 4 are ring heteroatoms, and include, forexample, —C₁₋₉heteroaryl and —C₅₋₉heteroaryl. Representative heteroarylgroups include, by way of example, pyrrole (e.g., 3-pyrrolyl and2H-pyrrol-3-yl), imidazole (e.g., 2-imidazolyl), furan (e.g., 2-furyland 3-furyl), thiophene (e.g., 2-thienyl), triazole (e.g.,1,2,3-triazolyl and 1,2,4-triazolyl), pyrazole (e.g., 1H-pyrazol-3-yl),oxazole (e.g., 2-oxazolyl), isoxazole (e.g., 3-isoxazolyl), thiazole(e.g., 2-thiazolyl and 4-thiazolyl), and isothiazole (e.g.,3-isothiazolyl), pyridine (e.g., 2-pyridyl, 3-pyridyl, and 4-pyridyl),pyridylimidazole, pyridyltriazole, pyrazine, pyridazine (e.g.,3-pyridazinyl), pyrimidine (e.g., 2-pyrimidinyl), tetrazole, triazine(e.g., 1,3,5-triazinyl), indolyle (e.g., 1H-indol-2-yl, 1H-indol-4-yland 1H-indol-5-yl), benzofuran (e.g., benzofuran-5-yl), benzothiophene(e.g., benzo[b]thien-2-yl and benzo[b]thien-5-yl), benzimidazole,benzoxazole, benzothiazole, benzotriazole, quinoline (e.g., 2-quinolyl),isoquinoline, quinazoline, quinoxaline and the like.

Monovalent saturated heterocycles typically contain from 3 to 10 totalring atoms, of which 2 to 9 are ring carbon atoms, and 1 to 4 are ringheteroatoms, and include, for example —C₃₋₅heterocycle. Representativemonovalent saturated heterocycles include, by way of example, monovalentspecies of pyrrolidine, imidazolidine, pyrazolidine, piperidine,1,4-dioxane, morpholine, thiomorpholine, piperazine, 3-pyrroline and thelike. In some instances, moieties may be described as being takentogether to form a saturated —C₃₋₅heterocycle optionally containing anoxygen atom in the ring. Such groups include:

Monovalent partially unsaturated heterocycles typically contain from 3to 10 total ring atoms, of which 2 to 11 are ring carbon atoms, and 1 to3 are ring heteroatoms, and include, for example —C₃₋₅heterocycle and—C₂₋₁₂heterocycle. Representative monovalent partially unsaturatedheterocycles include, by way of example, pyran, benzopyran, benzodioxole(e.g., benzo[1,3]dioxol-5-yl), tetrahydropyridazine,2,5-dihydro-1H-pyrrole, dihydroimidazole, dihydrotriazole,dihydrooxazole, dihydroisoxazole, dihydrothiazole, dihydroisothiazole,dihydrooxadiazole, dihydrothiadiazole, tetrahydropyridazine,hexahydropyrroloquinoxaline, and dihydrooxadiazabenzo[e]azulene. In someinstances, moieties may be described as being taken together to form apartially unsaturated —C₃₋₅heterocycle. Such groups include:

The term “optionally substituted” means that group in question may beunsubstituted or it may be substituted one or several times, such as 1to 3 times, or 1 to 5 times, or 1 to 8 times. For example, a phenylgroup that is “optionally substituted” with halo atoms, may beunsubstituted, or it may contain 1, 2, 3, 4, or 5 halo atoms; and analkyl group that is “optionally substituted” with fluoro atoms may beunsubstituted, or it may contain 1, 2, 3, 4, 5, 6, 7, or 8 fluoro atoms.Similarly, a group that is “optionally substituted” with one or two—C₁₋₆alkyl groups, may be unsubstituted, or it may contain one or two—C₁₋₆alkyl groups.

As used herein, the phrase “having the formula” or “having thestructure” is not intended to be limiting and is used in the same waythat the term “comprising” is commonly used. For example, if onestructure is depicted, it is understood that all stereoisomer andtautomer forms are encompassed, unless stated otherwise.

The term “pharmaceutically acceptable” refers to a material that is notbiologically or otherwise unacceptable when used in the invention. Forexample, the term “pharmaceutically acceptable carrier” refers to amaterial that can be incorporated into a composition and administered toa patient without causing unacceptable biological effects or interactingin an unacceptable manner with other components of the composition. Suchpharmaceutically acceptable materials typically have met the requiredstandards of toxicological and manufacturing testing, and include thosematerials identified as suitable inactive ingredients by the U.S. Foodand Drug administration.

The term “pharmaceutically acceptable salt” means a salt prepared from abase or an acid which is acceptable for administration to a patient,such as a mammal (for example, salts having acceptable mammalian safetyfor a given dosage regime). However, it is understood that the saltscovered by the invention are not required to be pharmaceuticallyacceptable salts, such as salts of intermediate compounds that are notintended for administration to a patient. Pharmaceutically acceptablesalts can be derived from pharmaceutically acceptable inorganic ororganic bases and from pharmaceutically acceptable inorganic or organicacids. In addition, when a compound of formula I contains both a basicmoiety, such as an amine, pyridine or imidazole, and an acidic moietysuch as a carboxylic acid or tetrazole, zwitterions may be formed andare included within the term “salt” as used herein. Salts derived frompharmaceutically acceptable inorganic bases include ammonium, calcium,copper, ferric, ferrous, lithium, magnesium, manganic, manganous,potassium, sodium, and zinc salts, and the like. Salts derived frompharmaceutically acceptable organic bases include salts of primary,secondary and tertiary amines, including substituted amines, cyclicamines, naturally-occurring amines and the like, such as arginine,betaine, caffeine, choline, N,N′-dibenzylethylenediamine, diethylamine,2-diethylaminoethanol, 2-dimethylaminoethanol, ethanolamine,ethylenediamine, N-ethylmorpholine, N-ethylpiperidine, glucamine,glucosamine, histidine, hydrabamine, isopropylamine, lysine,methylglucamine, morpholine, piperazine, piperadine, polyamine resins,procaine, purines, theobromine, triethylamine, trimethylamine,tripropylamine, tromethamine and the like. Salts derived frompharmaceutically acceptable inorganic acids include salts of boric,carbonic, hydrohalic (hydrobromic, hydrochloric, hydrofluoric orhydroiodic), nitric, phosphoric, sulfamic and sulfuric acids. Saltsderived from pharmaceutically acceptable organic acids include salts ofaliphatic hydroxyl acids (for example, citric, gluconic, glycolic,lactic, lactobionic, malic, and tartaric acids), aliphaticmonocarboxylic acids (for example, acetic, butyric, formic, propionicand trifluoroacetic acids), amino acids (for example, aspartic andglutamic acids), aromatic carboxylic acids (for example, benzoic,p-chlorobenzoic, diphenylacetic, gentisic, hippuric, and triphenylaceticacids), aromatic hydroxyl acids (for example, o-hydroxybenzoic,p-hydroxybenzoic, 1-hydroxynaphthalene-2-carboxylic and3-hydroxynaphthalene-2-carboxylic acids), ascorbic, dicarboxylic acids(for example, fumaric, maleic, oxalic and succinic acids), glucoronic,mandelic, mucic, nicotinic, orotic, pamoic, pantothenic, sulfonic acids(for example, benzenesulfonic, camphosulfonic, edisylic, ethanesulfonic,isethionic, methanesulfonic, naphthalenesulfonic,naphthalene-1,5-disulfonic, naphthalene-2,6-disulfonic andp-toluenesulfonic acids), xinafoic acid, and the like.

As used herein, the term “prodrug” is intended to mean an inactive (orsignificantly less active) precursor of a drug that is converted intoits active form in the body under physiological conditions, for example,by normal metabolic processes. Such compounds may not possesspharmacological activity at NEP, but may be administered orally orparenterally and thereafter metabolized in the body to form compoundsthat are pharmacologically active at NEP. Exemplary prodrugs includeesters such as C₁₋₆alkylesters and aryl-C₁₋₆alkylesters. In oneembodiment, the active compound has a free carboxyl and the prodrug isan ester derivative thereof, i.e., the prodrug is an ester such as—C(O)OCH₂CH₃. Such ester prodrugs are then converted by solvolysis orunder physiological conditions to be the free carboxyl compound. Theterm is also intended to include certain protected derivatives ofcompounds of formula I that may be made prior to a final deprotectionstage. Thus, all protected derivatives and prodrugs of compounds formulaI are included within the scope of the invention.

The term “therapeutically effective amount” means an amount sufficientto effect treatment when administered to a patient in need thereof, thatis, the amount of drug needed to obtain the desired therapeutic effect.For example, a therapeutically effective amount for treatinghypertension is an amount of compound needed to, for example, reduce,suppress, eliminate, or prevent the symptoms of hypertension, or totreat the underlying cause of hypertension. In one embodiment, atherapeutically effective amount is that amount of drug needed to reduceblood pressure or the amount of drug needed to maintain normal bloodpressure. On the other hand, the term “effective amount” means an amountsufficient to obtain a desired result, which may not necessarily be atherapeutic result. For example, when studying a system comprising a NEPenzyme, an “effective amount” may be the amount needed to inhibit theenzyme.

The term “treating” or “treatment” as used herein means the treating ortreatment of a disease or medical condition (such as hypertension) in apatient, such as a mammal (particularly a human) that includes one ormore of the following: (a) preventing the disease or medical conditionfrom occurring, i.e., preventing the reoccurrence of the disease ormedical condition or prophylactic treatment of a patient that ispre-disposed to the disease or medical condition; (b) ameliorating thedisease or medical condition, i.e., eliminating or causing regression ofthe disease or medical condition in a patient; (c) suppressing thedisease or medical condition, i.e., slowing or arresting the developmentof the disease or medical condition in a patient; or (d) alleviating thesymptoms of the disease or medical condition in a patient. For example,the term “treating hypertension” would include preventing hypertensionfrom occurring, ameliorating hypertension, suppressing hypertension, andalleviating the symptoms of hypertension (for example, lowering bloodpressure). The term “patient” is intended to include those mammals, suchas humans, that are in need of treatment or disease prevention or thatare presently being treated for disease prevention or treatment of aspecific disease or medical condition, as well as test subjects in whichcompounds of the invention are being evaluated or being used in anassay, for example an animal model.

All other terms used herein are intended to have their ordinary meaningas understood by those of ordinary skill in the art to which theypertain.

In one aspect, the invention relates to compounds of formula I:

or a pharmaceutically acceptable salt thereof.

As used herein, the term “compound of the invention” includes allcompounds encompassed by formula I such as the species embodied informulas Ia-d, as well as the compounds encompassed by formulas II, andIII, and species thereof. In addition, the compounds of the inventionmay also contain several basic or acidic groups (for example, amino orcarboxyl groups) and therefore, such compounds can exist as a free base,free acid, or in various salt forms. All such salt forms are includedwithin the scope of the invention. Furthermore, the compounds of theinvention may also exist as prodrugs. Accordingly, those skilled in theart will recognize that reference to a compound herein, for example,reference to a “compound of the invention” or a “compound of formula I”includes a compound of formula I as well as pharmaceutically acceptablesalts and prodrugs of that compound unless otherwise indicated. Further,the term “or a pharmaceutically acceptable salt and/or prodrug thereof”is intended to include all permutations of salts and prodrugs, such as apharmaceutically acceptable salt of a prodrug. Furthermore, solvates ofcompounds of formula I are included within the scope of this invention.

The compounds of formula I may contain one or more chiral centers andtherefore, these compounds may be prepared and used in variousstereoisomeric forms. Accordingly, the invention also relates to racemicmixtures, pure stereoisomers (e.g., enantiomers and diastereoisomers),stereoisomer-enriched mixtures, and the like unless otherwise indicated.When a chemical structure is depicted herein without anystereochemistry, it is understood that all possible stereoisomers areencompassed by such structure. Thus, for example, the terms “compound offormula I,” “compounds of formula II,” and so forth, are intended toinclude all possible stereoisomers of the compound. Similarly, when aparticular stereoisomer is shown or named herein, it will be understoodby those skilled in the art that minor amounts of other stereoisomersmay be present in the compositions of the invention unless otherwiseindicated, provided that the utility of the composition as a whole isnot eliminated by the presence of such other isomers. Individualstereoisomers may be obtained by numerous methods that are well known inthe art, including chiral chromatography using a suitable chiralstationary phase or support, or by chemically converting them intodiastereoisomers, separating the diastereoisomers by conventional meanssuch as chromatography or recrystallization, then regenerating theoriginal stereoisomer.

Additionally, where applicable, all cis-trans or E/Z isomers (geometricisomers), tautomeric forms and topoisomeric forms of the compounds ofthe invention are included within the scope of the invention unlessotherwise specified. For example, if X is depicted as (R⁴ beinghydrogen):

it is understood that the compound may also exist in a tautomeric formsuch as:

More specifically, compounds of formula I can contain at least twochiral centers indicated by the symbols * and ** in the followingformula:

In one stereoisomer, both carbon atoms identified by the * and **symbols have the (R) configuration. This embodiment of the invention isshown in formula Ia:

In this embodiment, compounds have the (R,R) configuration at the * and** carbon atoms or are enriched in a stereoisomeric form having the(R,R) configuration at these carbon atoms.

In another stereoisomer, both carbon atoms identified by the * and **symbols have the (S) configuration. This embodiment of the invention isshown in formula Ib:

In this embodiment, compounds have the (S,S) configuration at the * and** carbon atoms or are enriched in a stereoisomeric form having the(S,S) configuration at these carbon atoms.

In yet another stereoisomer, the carbon atom identified by the symbol *has the (S) configuration and the carbon atom identified by the symbol** has the (R) configuration. This embodiment of the invention is shownin formula Ic:

In this embodiment, compounds have the (S,R) configuration at the * and** carbon atoms or are enriched in a stereoisomeric form having the(S,R) configuration at these carbon atoms.

In still another stereoisomer, the carbon atom identified by thesymbol * has the (R) configuration and the carbon atom identified by thesymbol ** has the (S) configuration. This embodiment of the invention isshown in formula Id:

In this embodiment, compounds have the (R,S) configuration at the * and** carbon atoms or are enriched in a stereoisomeric form having the(R,S) configuration at these carbon atoms.

Compounds of formula Ia and Ib are enantiomers and therefore, inseparate aspects, this invention relates to each individual enantiomer(i.e., Ia or Ib), a racemic mixture of Ia and Ib, or anenantiomer-enriched mixture of Ia and Ib comprising predominately Ia orpredominately Ib. Similarly, compounds of formula Ic and Id areenantiomers and therefore, in separate aspects, this invention relatesto each individual enantiomer (i.e., Ic or Id), a racemic mixture of Icand Id, or an enantiomer-enriched mixture of Ic and Id comprisingpredominately Ic or predominately Id.

In some embodiments, in order to optimize the therapeutic activity ofthe compounds of the invention, e.g., to treat hypertension, it may bedesirable that the carbon atoms identified by the * and ** symbols havea particular (R,R), (S,S), (S,R), or (R,S) configuration or are enrichedin a stereoisomeric form having such configuration. For example, in oneembodiment, the compounds of the invention have the (S,R) configurationof formula Ic or are enriched in a stereoisomeric form having the (S,R)configuration, and in another embodiment, the compounds of the inventionhave the (R,S) configuration of formula Id, or are enriched in astereoisomeric form having the (R,S) configuration. In otherembodiments, the compounds of the invention are present as racemicmixtures, for example as a mixture of enantiomers of formula Ia and Ib,or as a mixture of enantiomers of formula Ic and Id.

The compounds of the invention, as well as those compounds used in theirsynthesis, may also include isotopically-labeled compounds, that is,where one or more atoms have been enriched with atoms having an atomicmass different from the atomic mass predominately found in nature.Examples of isotopes that may be incorporated into the compounds offormula I, for example, include, but are not limited to, ²H, ³H, ¹³C,¹⁴C, ¹⁵N, ¹⁸O, ¹⁷O, ³⁵S, ³⁶Cl, and ¹⁸F. Of particular interest arecompounds of formula I enriched in tritium or carbon-14 which can beused, for example, in tissue distribution studies; compounds of formulaI enriched in deuterium especially at a site of metabolism resulting,for example, in compounds having greater metabolic stability; andcompounds of formula I enriched in a positron emitting isotope, such as¹¹C, ¹⁸F, ¹⁵O and ¹³N, which can be used, for example, in PositronEmission Topography (PET) studies.

The nomenclature used herein to name the compounds of the invention isillustrated in the Examples herein. This nomenclature has been derivedusing the commercially available AutoNom software (MDL, San Leandro,Calif.).

Representative Embodiments

The following substituents and values are intended to providerepresentative examples of various aspects and embodiments of theinvention. These representative values are intended to further defineand illustrate such aspects and embodiments and are not intended toexclude other embodiments or to limit the scope of the invention. Inthis regard, the representation that a particular value or substituentis preferred is not intended in any way to exclude other values orsubstituents from the invention unless specifically indicated.

In one aspect, this invention relates to compounds of formula I:

R¹ is selected from —OR⁷ and —NR⁸R⁹. The R⁷ moiety is selected from:

H;

—C₁₋₈alkyl, e.g., —CH₃, —CH₂CH₃, —(CH₂)₂CH₃, —CH(CH₃)₂, —CH₂CH(CH₃)₂,—(CH₂)₃CH₃, —(CH₂)₄CH₃, —(CH₂)₂CH(CH₃)₂, —(CH₂)₅CH₃, and —(CH₂)₆CH₃;

—C₁₋₃alkylene-C₆₋₁₀aryl, e.g., benzyl;

—C₁₋₃alkylene-C₁₋₉heteroaryl, e.g., —CH₂-pyridinyl and—(CH₂)₂-pyridinyl;

—C₃₋₇cycloalkyl, e.g., cyclopentyl;

—[(CH₂)₂O]₁₋₃CH₃, e.g., —(CH₂)₂OCH₃ and —[(CH₂)₂O]₂CH₃;

—C₁₋₆alkylene-OC(O)R¹⁰, e.g., —CH₂OC(O)CH₃, —CH₂OC(O)CH₂CH₃,—CH₂OC(O)(CH₂)₂CH₃, —CH₂CH(CH₃)OC(O)CH₂CH₃, —CH₂OC(O)OCH₃,—CH₂OC(O)OCH₂CH₃, —CH(CH₃)OC(O)OCH₂CH₃, —CH(CH₃)OC(O)O—CH(CH₃)₂,—CH₂CH(CH₃)OC(O)-cyclopentyl, —CH₂OC(O)O-cyclopropyl, —CH(CH₃)—OC(O)—O—cyclohexyl, —CH₂OC(O)O-cyclopentyl, —CH₂CH(CH₃)OC(O)-phenyl, —CH₂OC(O)O—phenyl, —CH₂OC(O)—CH[CH(CH₃)₂]—NH₂, —CH₂OC(O)—CH[CH(CH₃)₂]—NHC(O)OCH₃,and —CH(CH₃)OC(O)—CH(NH₂)CH₂COOCH₃;

—C₁₋₆alkylene-NR¹²R¹³, e.g., —(CH₂)₂—N(CH₃)₂,

—C₁₋₆alkylene-C(O)R³¹, e.g., —CH₂C(O)OCH₃, —CH₂C(O)O-benzyl,—CH₂C(O)—N(CH₃)₂, and

—C₀₋₆alkylenemorpholinyl, e.g., —(CH₂)₂-morpholinyl and—(CH₂)₃-morpholinyl:

—C₁₋₆alkylene-SO₂—C₁₋₆alkyl, e.g., —(CH₂)₂SO₂CH₃;

for example,

The R¹⁰ moiety is selected from:

—C₁₋₆alkyl, e.g., —CH₃ and —CH₂CH₃;

—O—C₁₋₆alkyl, e.g., —OCH₃, —O—CH₂CH₃, and —O—CH(CH₃)₂;

—C₃₋₇cycloalkyl, e.g., cyclopentyl);

—O—C₃₋₇cycloalkyl, e.g., —O-cyclopropyl, —O-cyclohexyl, and—O-cyclopentyl;

phenyl;

—O-phenyl;

—NR¹²R¹³;

—CH[CH(CH₃)₂]—NH₂;

—CH[CH(CH₃)₂]—NHC(O)O—C₁₋₆alkyl, e.g., —CH[CH(CH₃)₂]—NHC(O)OCH₃; and

—CH(NH₂)CH₂COOCH₃.

The R¹² and R¹³ moieties are independently selected from H, —C₁₋₆alkyl(e.g., CH₃), and benzyl. Alternately, the R¹² and R¹³ moieties can betaken together as —(CH₂)₃₋₆—, —C(O)—(CH₂)₃—, or —(CH₂)₂O(CH₂)₂—, forexample to form a group such as:

The R³¹ moiety is selected from —O—C₁₋₆alkyl, e.g., —OCH₃, —O-benzyl,and —NR¹²R¹³, e.g., —N(CH₃)₂, and

The R³² moiety is —C₁₋₆alkyl (e.g., —CH₃ and —C(CH₃)₃) or—C₀₋₆alkylene-C₆₋₁₀aryl.

The R⁸ moiety is selected from:

H;

—OH;

—OC(O)R¹⁴, e.g., —OC(O)CH₃, —OC(O)-phenyl, —OC(O)—OCH₂-phenyl,—OC(O)—CH₂O-phenyl, —OC(O)(NH₂), and —OC(O)[N(CH₃)₂;

—CH₂COOH;

—O-benzyl;

pyridyl; and

—OC(S)NR¹⁵R¹⁶, e.g., —OC(S)NH₂ and —OC(S)N(CH₃)₂.

The R¹⁴ moiety is selected from:

H;

—C₁₋₆alkyl, e.g., —CH₃;

—C₆₋₁₀aryl, e.g., phenyl;

—OCH₂—C₆₋₁₀aryl, e.g., —OCH₂-phenyl;

—CH₂O—C₆₋₁₀aryl, e.g., —CH₂O-phenyl; and

—NR¹⁵R¹⁶, e.g., —NH₂ and N(CH₃)₂.

The R¹⁵ and R¹⁶ moieties are independently selected from H and—C₁₋₄alkyl.

The R⁹ is moiety selected from H, —C₁₋₆alkyl (e.g., —CH₃), and —C(O)R¹⁷(e.g., —C(O)H). The R¹⁷ moiety is selected from H, —C₁₋₆alkyl (e.g.,—CH₂CH₃), —C₃₋₇cycloalkyl (e.g., cyclopropyl), —C₆₋₁₀aryl (e.g.,phenyl), and —C₁₋₉heteroaryl (e.g., pyridine).

In addition, each alkyl group in R¹ is optionally substituted with 1 to8 fluoro atoms. For example, when R¹ is —OR⁷ and R⁷ is —C₁₋₈alkyl, R¹can also be a group such as —OCH(CH₃)CF₃, —OCH₂CF₂CF₃, —OCH(CF₃)₂,—O(CH₂)₂CF₃, —OCH(CH₂F)₂, —OC(CF₃)₂CH₃, and —OCH(CH₃)CF₂CF₃.

In one embodiment, R¹ is selected from —OR⁷, where R⁷ is selected fromH, —C₁₋₈alkyl, —C₁₋₆alkylene-OC(O)R¹⁰, —C₀₋₆alkylenemorpholinyl,—C₁₋₆alkylene-SO₂—C₁₋₆alkyl, and

where R¹⁰ is —O—C₃₋₇cycloalkyl; and —NR⁸R⁹, where R⁸ is H and R⁹ is H.In another embodiment these compounds have formula III.

In one embodiment, R¹ is selected from —OR⁷ and —NR⁸R⁹, where R⁷ is H,R⁸ is H or —OH, and R⁹ is H. In another embodiment these compounds haveformula III.

In another embodiment, R¹ is —OR⁷, where R⁷ is selected from —C₁₋₈alkyl,—C₁₋₃alkylene-C₆₋₁₀aryl, —C₁₋₃alkylene-C₁₋₉heteroaryl, —C₃₋₇cycloalkyl,—[(CH₂)₂O]₁₋₃CH₃, —C₁₋₆alkylene-OC(O)R¹⁰, —C₁₋₆alkylene-NR¹²R¹³,—C₁₋₆alkylene-C(O)R³¹, —C₀₋₆alkylenemorpholinyl;—C₁₋₆alkylene-SO₂—C₁₋₆alkyl;

In yet another embodiment, R¹ is —NR⁸R⁹; where R⁸ is selected from—OC(O)R¹⁴, —CH₂COOH, —O-benzyl, pyridyl, and —OC(S)NR¹⁵R¹⁶; and R⁹ is H.In yet another embodiment, R¹ is —NR⁸R⁹, where R⁸ is H or —OH; and R⁹ is—C₁₋₆alkyl or —C(O)R¹⁷. In yet another embodiment, R¹ is —NR⁸R⁹, whereR⁸ is selected from —OC(O)R¹⁴, —CH₂COOH, —O-benzyl, pyridyl, and—OC(S)NR¹⁵R¹⁶; and R⁹ is —C₁₋₆alkyl or —C(O)R¹⁷. In another embodimentthese compounds have formula III. In one aspect of the invention, thesecompounds may find particular utility as prodrugs or as intermediates inthe synthetic procedures described herein. For example, in oneembodiment, R¹ is —OR⁷ and R⁷ is —C₁₋₆alkylene-OC(O)R¹⁰, such as—O—CH(CH₃)OC(O)—O-cyclohexyl:

making the compound a cilexetil ester; or R¹ is —OR⁷ and R⁷ is—C₀₋₆alkylenemorpholinyl such as —O—(CH₂)₂-morpholinyl:

making the compound a 2-morpholinoethyl or mofetil ester; or R¹ is —OR⁷and R⁷ is

such as —O—CH₂-5-methyl-[1,3]dioxol-2-one:

making the compound a medoxomil ester.

R² is H or —P(O)(OH)₂. R² can also be taken together with R⁷ to form—CR¹⁸R¹⁹— or taken together with R⁸ to form —C(O)—. R¹⁸ and R¹⁹ areindependently selected from H, —C₁₋₆alkyl, and —O—C₃₋₇cycloalkyl, or R¹⁸and R¹⁹ may be taken together to form ═O. In one embodiment, R² is H. Inanother embodiment this compound has formula III.

When R² is taken together with R⁷ to form —CR¹⁸R¹⁹—, this embodiment canbe depicted as:

and when R¹⁸ and R¹⁹ are taken together to form ═O, this embodiment canbe depicted as:

When R² is taken together with R⁸ to form —C(O)—, this embodiment can bedepicted as:

In one aspect of the invention, these compounds may find particularutility as prodrugs or as intermediates in the synthetic proceduresdescribed herein. In another embodiment these compounds have formulaIII. Compounds where R² is —P(O)(OH)₂ may also find utility as prodrugs.

The “X” moiety is a —C₁₋₉heteroaryl, and the point of attachment is atany available carbon or nitrogen ring atom. Note that in someembodiments, R³ and/or R⁴ may be absent. When present, R³ is on anyavailable carbon atom. When present, R⁴ is on any available carbon atomor nitrogen atom. Exemplary —C₁₋₉heteroaryl rings include, by way ofillustration and not limitation:

pyrazole rings such as:

specific examples of which include:

imidazole rings such as:

specific examples of which include:

triazole rings, including 1,2,3-triazole such as:

as well as 1,2,4-triazole such as:

benzotriazole rings such as:

specific examples of which include:

furan rings:

specific examples of which include:

pyrrole rings:

specific examples of which include:

tetrazole rings such as:

pyrazine rings:

a specific example of which includes:

thiophene rings:

a specific example of which includes:

oxazole rings;

specific examples of which include:

isoxazole rings:

specific examples of which include:

thiazole rings:

specific examples of which include:

isothiazole rings:

oxadiazole rings, including [1,2,4]oxadiazole such as:

as well as [1,2,3]oxadiazole such as:

and [1,3,4]oxadiazole:

thiadiazole rings, including [1,2,4]thiadiazole such as:

as well as [1,2,3]thiadiazole such as:

and [1,3,4]thiadiazole:

pyridazine rings:

pyridine rings:

specific examples of which include:

pyrimidine rings:

specific examples of which include:

pyran rings such as

benzimidazole rings such as:

specific examples of which include:

benzoxazole rings such as:

specific examples of which include:

benzothiazole rings such as:

specific examples of which include:

pyridylimidazole rings such as:

a specific example of which includes:

pyridyltriazole rings such as:

specific examples of which include:

In one particular embodiment, X is selected from pyrazole, imidazole,triazole, benzotriazole, furan, pyrrole, tetrazole, pyrazine, thiophene,oxazole, isoxazole, thiazole, isothiazole, oxadiazole, thiadiazole,pyridazine, pyridine, pyrimidine, pyran, benzimidazole, benzoxazole,benzothiazole, pyridylimidazole, and pyridyltriazole.

It is understood that some —C₁₋₉heteroaryl rings can exist in atautomeric form, and that such tautomeric forms are part of theinvention and are encompassed by the term “heteroaryl.” Therefore, if acompound is depicted with a —C₁₋₉heteroaryl ring, it is understood thatthe compound can also exist in a tautomeric form and vice versa, andthat both forms are covered by the invention.

—C₁₋₉ heteroaryl ring exemplary ring exemplary tautomer(s) pyrazole

imidazole

triazole

oxazole

thiazole

isothiazole

oxadiazole

thiadiazole

pyridazine

In one particular embodiment, X is selected from pyrazole, triazole,benzotriazole, furan, tetrazole, pyrazine, thiophene, oxazole,isoxazole, thiazole, oxadiazole, pyridazine, pyridine, pyrimidine,benzoxazole, pyridylimidazole, and pyridyltriazole. In anotherembodiment, X is selected from pyrazole, triazole, benzotriazole,isoxazole, pyridazine, pyrimidine, and pyridyltriazole. In still anotherembodiment X is an isoxazole, and in one specific embodiment, haveformula III:

where R¹-R⁶, a, and b are as defined for formula I. In yet anotherembodiment, the compounds of the invention have formula IIIa:

where R¹, R⁵, R⁶, a, and b, are as defined for formula I. In stillanother embodiment, the compounds of the invention have formula IIIb:

where R¹, R⁵, R⁶, a, and b, are as defined for formula I.

The R³ moiety can be absent. When present, R³ is attached to a carbonatom in the “X” group, and is selected from:

H;

halo, e.g., chloro and fluoro;

—C₀₋₅alkylene-OH, e.g., —OH, —CH₂OH, —CH(OH)CH₃, and —C(CH₃)₂—OH;

—NH₂;

—C₁₋₆alkyl, e.g., —CH₃, —(CH₂)₂CH₃, —CH(CH₃)₂, and —(CH₂)₃—CH₃;

—CF₃;

—C₃₋₇cycloalkyl, e.g., cyclopropyl and cyclohexyl;

—C₀₋₂alkylene-O—C₁₋₆alkyl, e.g., —OCH₃, —OCH₂CH₃, —CH₂—OCH₃, and—(CH₂)₂—OCH₃;

—C(O)R²⁰, e.g., —C(O)H and —C(O)CH₃;

—C₀₋₁alkylene-COOR²¹, e.g., —COOH, —CH₂—COOH, —C(O)O—CH₂CH₃,—C(O)O—(CH₂)₂OCH₃—C(O)O—CH₂OC(O)CH₃, —CH₂—C(O)O—CH₂OC(O)CH₃,—C(O)O—CH₂OC(O)O—CH₃, —CH₂—C(O)O—CH₂OC(O)O—CH₃,—C(O)O—CH(CH₃)OC(O)O—CH₂CH₃, —C(O)O—CH(CH₃)OC(O)O—CH(CH₃)₂,—C(O)O—CH₂CH(CH₃)OC(O)-cyclopentyl, —C(O)O—CH₂OC(O)O-cyclopropyl,—C(O)O—CH(CH₃)—OC(O)—O-cyclohexyl, —C(O)O—CH₂OC(O)O— cyclopentyl,—C(O)O—CH₂CH(CH₃)OC(O)-phenyl, —C(O)O—CH₂OC(O)O-phenyl,—C(O)O—CH₂-pyridine, —C(O)O—CH₂-pyrrolidine, —C(O)O—(CH₂)₂-morpholinyl,—C(O)O—(CH₂)₃-morpholinyl, and —C(O)O—(CH₂)₂—SO₂—CH₃;

—C(O)NR²²R²³, e.g., —C(O)NH₂, —C(O)NHCH₃, —C(O)N(CH₃)₂,—C(O)NH—(CH₂)₂CH₃, —C(O)NH—CH₂COOH, —C(O)NH—(CH₂)₂—OH,—C(O)NH—(CH₂)₂—N(CH₃)₂, —C(O)NH-cyclopropyl, —C(O)NH—(CH₂)₂-imidazolyl,—C(O)N(CH₃)—CH₂CH(CH₃)₂, and —C(O)N(CH₃)[(CH₂)₂OCH₃];

—NHC(O)R²⁴, e.g., —NHC(O)—CH₂CH₃, —NHC(O)—(CH₂)₃CH₃, —NHC(O)O—CH₂CH₃,—NHC(O)—CH₂—OCH₃, —NHC(O)-2-methoxyphenyl, —NHC(O)-2-chlorophenyl, and—NHC(O)-2-pyridine;

═O;

—NO₂;

—C(CH₃)═N(OH);

phenyl optionally substituted with one or two groups independentlyselected from halo, —OH, —CF₃, —OCH₃, —NHC(O)CH₃, and phenyl (e.g.,phenyl, 2-chlorophenyl, 2-fluorophenyl, 2-hydroxyphenyl,2-trifluoromethylphenyl, 2-methoxyphenyl, 3-chlorophenyl,3-fluorophenyl, 3-methoxyphenyl, 3-NHC(O)CH₃-phenyl, 4-chlorophenyl,4-fluorophenyl, 4-methoxyphenyl, 4-biphenyl, 2,5-dichlorophenyl,2,5-dimethoxyphenyl, 2,4-dichlorophenyl, 2-methoxy, 5-fluorophenyl, and3,4-dichlorophenyl); naphthalenyl;

pyridinyl;

pyrazinyl;

pyrazolyl optionally substituted with methyl;

thiophenyl optionally substituted with methyl or halo (e.g., chloro);

furanyl; and

—CH₂-morpholinyl.

The R²⁰ moiety is selected from H and —C₁₋₆alkyl (e.g., —CH₃). The R²¹moiety is selected from:

H;

—C₁₋₆ alkyl, e.g., —CH₃ and —CH₂CH₃;

—C₁₋₃alkylene-C₆₋₁₀aryl;

—C₁₋₃alkylene-C₁₋₉heteroaryl, e.g., —CH₂-pyridine;

—C₃₋₇cycloalkyl;

—[(CH₂)₂O]₁₋₃CH₃, e.g., —(CH₂)₂OCH₃;

—C₁₋₆alkylene-OC(O)R²⁵, e.g., —CH₂OC(O)CH₃, —CH₂OC(O)O—CH₃,—CH₂OC(O)O—CH₃, —CH(CH₃)OC(O)O—CH₂CH₃, —CH(CH₃)OC(O)O—CH(CH₃)₂,—CH₂CH(CH₃)OC(O)-cyclopentyl, —CH₂OC(O)O-cyclopropyl,—CH(CH₃)—OC(O)—O-cyclohexyl, —CH₂OC(O)O— cyclopentyl,—CH₂CH(CH₃)OC(O)-phenyl, and —CH₂OC(O)O-phenyl;

—C₁₋₆alkylene-NR²⁷R²⁸, e.g., —CH₂-pyrrolidine;

—C₁₋₆alkylene-C(O)R³³;

—C₀₋₆alkylenemorpholinyl, e.g., —(CH₂)₂-morpholinyl and—(CH₂)₃-morpholinyl:

—C₁₋₆alkylene-SO₂—C₁₋₆alkyl, e.g., —(CH₂)₂—SO₂—CH₃;

The R²² and R²³ moieties are independently selected from:

H;

—C₁₋₆alkyl, e.g., —CH₃ and —(CH₂)₂CH₃;

—CH₂COOH;

—(CH₂)₂OH;

—(CH₂)₂OCH₃;

—(CH₂)₂SO₂NH₂;

—(CH₂)₂N(CH₃)₂;

—C₀₋₁alkylene-C₃₋₇cycloalkyl, e.g., cyclopropyl and —CH₂-cyclopropyl;and

—(CH₂)₂-imidazolyl.

R²² and R²³ may also be taken together to form a saturated or partiallyunsaturated —C₃₋₅heterocycle optionally substituted with halo, —OH,—COOH, or —CONH₂, and optionally containing an oxygen atom in the ring.Saturated —C₃₋₅heterocycles include azetidine, pyrrolidine, piperidineand morpholine, such that exemplary R³ groups include:

Partially unsaturated —C₃₋₅heterocycles include 2,5-dihydro-1H-pyrrole,such that exemplary R³ groups include:

The R²⁴ moiety is selected from:

—C₁₋₆alkyl, e.g., —CH₂CH₃ and —(CH₂)₃CH₃;

—C₀₋₁alkylene-O—C₁₋₆alkyl, e.g., —O—CH₂CH₃ and —CH₂—OCH₃;

phenyl optionally substituted with halo or —OCH₃, e.g., -2chlorophenylor -2-methoxyphenyl; and

—C₁₋₉heteroaryl, e.g., 2-pyridine.

R²⁵ is selected from:

—C₁₋₆alkyl, e.g., —CH₃, —CH₂CH₃, and —(CH₂)₃CH₃;

—O—C₁₋₆alkyl, e.g., —OCH₃, —OCH₂CH₃, and —OCH(CH₃)₂;

—C₃₋₇cycloalkyl, e.g., cyclopentyl;

—O—C₃₋₇cycloalkyl, e.g., —O-cyclopropyl, —O-cyclopentyl, and—O-cyclohexyl;

phenyl;

—O-phenyl;

—NR²⁷R²⁸;

—CH[CH(CH₃)₂]—NH₂;

—CH[CH(CH₃)₂]—NHC(O)O—C₁₋₆alkyl, e.g., —CH[CH(CH₃)₂]—NHC(O)OCH₃; and

—CH(NH₂)CH₂COOCH₃.

R²⁷ and R²⁸ are independently selected from H, —C₁₋₆alkyl, and benzyl,or R²⁷ and R²⁸ are taken together as —(CH₂)₃₋₆—, —C(O)—(CH₂)₃—, or—(CH₂)₂O(CH₂)₂—; R³³ is selected from —O—C₁₋₆alkyl, —O-benzyl, and—NR²⁷R²⁸; and R³⁴ is —C₁₋₆alkyl (e.g., —CH₃ and —C(CH₃)₃) or—C₀₋₆alkylene-C₆₋₁₀aryl.

In addition, each alkyl group in R³ is optionally substituted with 1 to8 fluoro atoms. For example, when R³ is —C₀₋₁alkylene-COOR²¹ and R²¹ is—C₁₋₆alkyl, R³ can also be a group such as —COOCH(CH₃)CF₃,—COOCH₂CF₂CF₃, —COOCH(CF₃)₂, —COO(CH₂)₂CF₃, —COOCH(CH₂F)₂,—COOC(CF₃)₂CH₃, and —COOCH(CH₃)CF₂CF₃.

In one embodiment, R³ is absent or is selected from H; halo;—C₀₋₅alkylene-OH; —NH₂; —C₁₋₆alkyl; —CF₃; —C₃₋₇cycloalkyl;—C₀₋₂alkylene-O—C₁₋₆alkyl; —C(O)R²⁰; —C₀₋₁alkylene-COOR²¹; —C(O)NR²²R²³;—NHC(O)R²⁴; ═O; —C(CH₃)═N(OH); phenyl optionally substituted with one ortwo groups independently selected from halo, —OH, —CF₃, —OCH₃,—NHC(O)CH₃, and phenyl; naphthalenyl; pyridinyl; pyrazinyl; pyrazolylsubstituted with methyl; thiophenyl substituted with methyl or halo;furanyl; and —CH₂— morpholinyl; R²⁰ is —C₁₋₆alkyl; R²¹ is selected fromH and —C₁₋₆alkyl; R²² is selected from H and —C₁₋₆alkyl; and R²³ isselected from H, —C₁₋₆alkyl, —CH₂COOH, —(CH₂)₂OH, —(CH₂)₂OCH₃,—(CH₂)₂N(CH₃)₂, —C₃₋₇cycloalkyl, and —(CH₂)₂-imidazolyl; or R²² and R²³are taken together to form azetidine, pyrrolidine, piperidine ormorpholine, all optionally substituted with —OH or —CONH₂; and R²⁴ isselected from —C₁₋₆alkyl; —C₀₋₁alkylene-O—C₁₋₆alkyl; phenyl substitutedwith halo or —OCH₃; and pyridine. In other embodiments these compoundshave formula III.

In one embodiment, R³ is absent or is selected from H; halo;—C₀₋₅alkylene-OH; —NH₂; —C₁₋₆alkyl; —CF₃; —C₃₋₇cycloalkyl;—C₀₋₂alkylene-O—C₁₋₆alkyl; —C(O)R²⁰; —C₀₋₁alkylene-COOR²¹; —C(O)NR²²R²³;—NHC(O)R²⁴; ═O; —NO₂; —C(CH₃)═N(OH); phenyl optionally substituted withone or two groups independently selected from halo, —OH, —CF₃, —OCH₃,—NHC(O)CH₃, and phenyl; naphthalenyl; pyridinyl; pyrazinyl; pyrazolyloptionally substituted with methyl; thiophenyl optionally substitutedwith methyl or halo; furanyl; and —CH₂-morpholinyl; and R²¹ is H. Inother embodiments these compounds have formula III.

In another embodiment, R³ is —C₀₋₁alkylene-COOR²¹, and R²¹ is selectedfrom —C₁₋₆alkyl, —C₁₋₃alkylene-C₆₋₁₀aryl, —C₁₋₃alkylene-C₁₋₉heteroaryl,—C₃₋₇cycloalkyl, —[(CH₂)₂O]₁₋₃CH₃, —C₁₋₆alkylene-OC(O)R²⁵;—C₁₋₆alkylene-NR²⁷R²⁸, —C₁₋₆alkylene-C(O)R³³, —C₀₋₆alkylenemorpholinyl,—C₁₋₆alkylene-SO₂—C₁₋₆alkyl,

In one aspect of the invention, these compounds may find particularutility as prodrugs or as intermediates in the synthetic proceduresdescribed herein. In other embodiments these compounds have formula III.

The R⁴ moiety can be absent. When present, R⁴ is attached to a carbon ornitrogen atom in the “X” group, and is selected from: H;

—OH;

—C₁₋₆alkyl, e.g., —CH₃;

—C₁₋₂alkylene-COOR³⁵, e.g., —CH₂COOH and —(CH₂)₂—COOH;

—CH₂OC(O)CH(R³⁶)NH₂, e.g., —CH₂OC(O)CH[CH(CH₃)₂]NH₂;

—OCH₂OC(O)CH(R³⁶)NH₂, e.g., —OCH₂OC(O)CH[CH(CH₃)₂]NH₂;

—OCH₂OC(O)CH₃;

—CH₂OP(O)(OH)₂;

—CH₂CH(OH)CH₂OH;

—CH[CH(CH₃)₂]—NHC(O)O—C₁₋₆alkyl;

pyridinyl; and

phenyl or benzyl optionally substituted with one or more groups selectedfrom halo, —COOR³⁵, —OCH₃, —OCF₃, and —SCF₃ (e.g., 4-chlorophenyl,3-methoxyphenyl, 2,4-dichlorophenyl, 3,4-dichlorophenyl, 2-chloro,5-fluorophenyl, 3-trifluoromethoxy, 4-chlorophenyl,3-trifluoromethylsulfanyl, 4-chlorophenyl, 2,6-difluoro, 4-chlorophenyl,2-chlorobenzyl, 3-chlorobenzyl, 4-chlorobenzyl, 3-carboxybenzyl,4-carboxybenzyl, 3-methoxybenzyl, 2-chloro, 5-fluorobenzyl, 3-chloro,5-fluorobenzyl, 2-fluoro, 4-chlorobenzyl, 3-chloro, 4-fluorobenzyl,3-OCF3, 4-chlorobenzyl, 3-SCF3, 4-chlorobenzyl, 2,6-difluoro,3-chlorobenzyl, 2,6-difluoro, 4-chlorobenzyl, and 2,3,5,6-tetrafluoro,4-methoxy benzyl).

The R³⁵ moiety is selected from:

H;

—C₁₋₆alkyl, e.g., —CH₃ and —CH₂CH₃;

—C₃alkylene-C₆₋₁₀aryl;

—C₁₋₃alkylene-C₁₋₉heteroaryl, e.g., —CH₂-pyridine;

—C₃₋₇cycloalkyl;

—[(CH₂)₂O]₁₋₃CH₃, e.g., —(CH₂)₂OCH₃;

—C₁₋₆alkylene-OC(O)R²⁵, e.g., —CH₂OC(O)CH₃, —CH₂OC(O)O—CH₃,—CH₂OC(O)O—CH₃, —CH(CH₃)OC(O)O—CH₂CH₃, —CH(CH₃)OC(O)O—CH(CH₃)₂,—CH₂CH(CH₃)OC(O)-cyclopentyl, —CH₂OC(O)O-cyclopropyl,—CH(CH₃)—OC(O)—O-cyclohexyl, —CH₂OC(O)O— cyclopentyl,—CH₂CH(CH₃)OC(O)-phenyl, and —CH₂OC(O)O-phenyl;

—C₁₋₆alkylene-NR²⁷R²⁸, e.g., —CH₂-pyrrolidine;

—C₁₋₆alkylene-C(O)R³³;

—C₀₋₆alkylenemorpholinyl, e.g., —(CH₂)₂-morpholinyl and—(CH₂)₃-morpholinyl:

—C₁₋₆alkylene-SO₂—C₁₋₆alkyl, e.g., —(CH₂)₂—SO₂—CH₃;

The R²⁵, R²⁷, R²⁸, R³³, and R³⁴ moieties are defined above. The R³⁶moiety is selected from H, —CH(CH₃)₂, phenyl, and benzyl.

In addition, each alkyl group in R⁴ is optionally substituted with 1 to8 fluoro atoms. For example, when R⁴ is —C₁₋₂alkylene-COOR³⁵ and R³⁵ is—C₁₋₆alkyl, R⁴ can also be a group such as —COOCH(CH₃)CF₃,—COOCH₂CF₂CF₃, —COOCH(CF₃)₂, —COO(CH₂)₂CF₃, —COOCH(CH₂F)₂,—COOC(CF₃)₂CH₃, and —COOCH(CH₃)CF₂CF₃.

The R⁴ moiety can also be taken together with R³ to form-phenylene-O—(CH₂)₁₋₃- or -phenylene-O—CH₂—CHOH—CH₂—. For purposes ofillustration only, these embodiments are depicted below with X beingpyrazole. It is understood that other X groups can be used also.

In another particular embodiment, R⁴ is absent or is selected from H;—OH; —C₁₋₆alkyl; —C₁₋₂alkylene-COOR³⁵; —CH₂OC(O)CH(R³⁶)NH₂;—CH₂CH(OH)CH₂OH; pyridinyl; phenyl optionally substituted with one halogroup; and benzyl optionally substituted with one or more groupsselected from halo, —COOH, —OCH₃, —OCF₃, and —SCF₃; R³⁵ is H; and R³⁶ is—CH(CH₃)₂; or R³ and R⁴ are taken together to form-phenylene-O—(CH₂)₁₋₃— or -phenylene-O—CH₂—CHOH—CH₂—. In otherembodiments these compounds have formula III.

In one embodiment, R⁴ is absent or is selected from H; —OH; —C₁₋₆alkyl;—C₁₋₂alkylene-COOR³⁵; —CH₂OC(O)CH(R³⁶)NH₂, —CH₂CH(OH)CH₂OH; pyridinyl;and phenyl or benzyl optionally substituted with one or more groupsselected from halo, —COOR³⁵, —OCH₃, —OCF₃, and —SCF₃; and R³⁵ is H. Inother embodiments these compounds have formula III.

In another embodiment, R⁴ is selected from —OCH₂OC(O)CH₃;—CH₂OP(O)(OH)₂; —C₁₋₂alkylene-COOR³⁵; and phenyl or benzyl substitutedwith at least one —COOR³⁵ group; where R³⁵ is selected from —C₁₋₆alkyl,—C₁₋₃alkylene-C₆₋₁₀aryl, —C₁₋₃alkylene-C₁₋₉heteroaryl, —C₃₋₇cycloalkyl,—[(CH₂)₂O]₁₋₃CH₃, —C₁₋₆alkylene-OC(O)R²⁵; —C₁₋₆alkylene-NR²⁷R²⁸,—C₁₋₆alkylene-C(O)R³³, —C₀₋₆alkylenemorpholinyl,—C₁₋₆alkylene-SO₂—C₁₋₆alkyl,

In one aspect of the invention, these compounds may find particularutility as prodrugs or as intermediates in the synthetic proceduresdescribed herein. In other embodiments these compounds have formula III.

The numbering for the R⁵ and R⁶ groups is as follows:

The integer “a” is 0 or 1. The R⁵ moiety, when present, is selected fromhalo, —CH₃, —CF₃, and —CN. In one embodiment, a is 0. In anotherembodiment, a is 1, and R⁵ is halo, such as 3-chloro or 3-fluoro. Theinteger “b” is 0 or an integer from 1 to 3. The R⁶ moiety, when present,is independently selected from halo, —OH, —CH₃, —OCH₃, and —CF₃. In oneembodiment, b is 0. In another embodiment, b is 1 and R⁶ is selectedfrom Cl, F, —OH, —CH₃, —OCH₃, and —CF₃, such 2′-chloro, 3′-chloro,2′-fluoro, 3′-fluoro, 2′-hydroxy, 3′-hydroxy, 3′-methyl, 2′-methoxy, or3′-trifluoromethyl. In another embodiment, b is 1 and R⁶ is halo, —CH₃,or —OCH₃, such 3′-chloro, 3′-methyl, or 2′-methoxy. In one embodiment, bis 2 and R⁶ is 2′-fluoro-5′-chloro, 2′,5′-dichloro, 2′,5′-difluoro,2′-methyl-5′-chloro, 3′-fluoro-5′-chloro, 3′-hydroxy-5′-chloro,3′,5′-dichloro, 3′,5′-difluoro, 2′-methoxy-5′-chloro,2′-methoxy-5′-fluoro, 2′-hydroxy-5′-fluoro, 2′-fluoro-3′-chloro,2′-hydroxy-5′-chloro, or 2′-hydroxy-3′-chloro; and in anotherembodiment, b is 2 and each R⁶ is independently halo, for example,2′-fluoro-5′-chloro and 2′,5′-dichloro. In another embodiment, b is 3and each R⁶ is independently halo or —CH₃, such as 2′-methyl-3′,5′-dichloro or 2′-fluoro-3′-methyl-5′-chloro. In yet another embodiment,a is 1 and b is 1 and R⁵ and R⁶ are independently halo, for example,3-chloro and 3′chloro. In other embodiments these compounds have formulaIII. Of particular interest are compounds of the formulas:

The methylene linker on the biphenyl is optionally substituted with oneor two —C₁₋₆alkyl groups or cyclopropyl. For example, in one embodiment,the methylene linker on the biphenyl is unsubstituted; in anotherembodiment, the methylene linker on the biphenyl is substituted with one—C₁₋₆alkyl group (e.g., —CH₃); and in yet another embodiment, themethylene linker on the biphenyl is substituted with two —C₁₋₆alkylgroups (e.g., two —CH₃ groups); in another embodiment, the methylenelinker on the biphenyl is substituted with a cyclopropyl group. Theseembodiments are depicted, respectively, as:

In another embodiment, R⁷ is selected from H, —C₁₋₈alkyl,—C₁₋₆alkylene-OC(O)R¹⁰, —C₀₋₆alkylenemorpholinyl,—C₁₋₆alkylene-SO₂—C₁₋₆alkyl, and

R¹⁰ is —O—C₃₋₇cycloalkyl; R⁸ is H; R⁹ is H; R² is H; R³ is absent or isselected from H; halo; —C₀₋₅alkylene-OH; —NH₂; —C₁₋₆alkyl; —CF₃;—C₃₋₇cycloalkyl; —C₀₋₂alkylene-O—C₁₋₆alkyl; —C(O)R²⁰;—C₀₋₁alkylene-COOR²¹; —C(O)NR²²R²³; —NHC(O)R²⁴; ═O; —C(CH₃)═N(OH);phenyl optionally substituted with one or two groups independentlyselected from halo, —OH, —CF₃, —OCH₃, —NHC(O)CH₃, and phenyl;naphthalenyl; pyridinyl; pyrazinyl; pyrazolyl substituted with methyl;thiophenyl substituted with methyl or halo; furanyl; and—CH₂-morpholinyl; R²⁰ is —C₁₋₆alkyl; R²¹ is H or —C₁₋₆alkyl; R²² is H or—C₁₋₆alkyl; and R²³ is selected from H, —C₁₋₆alkyl, —CH₂COOH, —(CH₂)₂OH,—(CH₂)₂OCH₃, —(CH₂)₂N(CH₃)₂, —C₃₋₇cycloalkyl, and —(CH₂)₂-imidazolyl; orR²² and R²³ are taken together to form azetidine, pyrrolidine,piperidine or morpholine, all optionally substituted with —OH or —CONH₂;and R²⁴ is selected from —C₁₋₆alkyl; —C₀₋₁alkylene-O—C₁₋₆alkyl; phenylsubstituted with halo or —OCH₃; and pyridinyl; R⁴ is absent or isselected from H; —OH; —C₁₋₆alkyl; —C₁₋₂alkylene-COOR³⁵;—CH₂OC(O)CH(R³⁶)NH₂; —CH₂CH(OH)CH₂OH; pyridinyl; phenyl optionallysubstituted with one halo group; and benzyl optionally substituted withone or more groups selected from halo, —COOH, —OCH₃, —OCF₃, and —SCF₃;R³⁵ is H; and R³⁶ is —CH(CH₃)₂; or R³ and R⁴ are taken together to form-phenylene-O—(CH₂)₁₋₃— or -phenylene-O—CH₂—CHOH—CH₂—; a is 0; or a is 1and R⁵ is 3-chloro; b is 0; or b is 1 and R⁶ is 3′-chloro, 3′-methyl, or2′-methoxy; or b is 2 and R⁶ is 2′-fluoro-5′-chloro, 2′,5′-dichloro,2′-methyl-5′-chloro, or 3′-chloro-5′-hydroxy; and the methylene linkeron the biphenyl is optionally substituted with 2 methyl groups. In oneembodiment, X is selected from pyrazole, triazole, benzotriazole, furan,tetrazole, pyrazine, thiophene, oxazole, isoxazole, thiazole,oxadiazole, pyridazine, pyridine, pyrimidine, benzoxazole,pyridylimidazole, and pyridyltriazole.

In still another embodiment, R¹ is —OR; R² is H; X is selected frompyrazole, triazole, benzotriazole, isoxazole, pyridazine, pyrimidine,and pyridyltriazole; R³ is selected from H; halo; —C₀₋₅alkylene-OH;—C₁₋₆alkyl; —CF₃; —C₃₋₇cycloalkyl; —C₀₋₂alkylene-O—C₁₋₆alkyl; —C(O)R²⁰;—C₀₋₁alkylene-COOR²¹; —C(O)NR²²R²³; —NHC(O)R²⁴; ═O; —C(CH₃)═N(OH);phenyl optionally substituted with one or two groups independentlyselected from halo, —OH, and —OCH₃; pyridinyl; pyrazinyl; and thiophenylsubstituted with methyl or halo; R⁴ is selected from H; —OH; —C₁₋₆alkyl;—C₁₋₂alkylene-COOR³⁵; —CH₂CH(OH)CH₂OH; pyridinyl; and phenyl optionallysubstituted with one halo group; or R³ and R⁴ are taken together to form-phenylene-O—(CH₂)₁₋₃—; a is 0; or a is 1 and R⁵ is 3-chloro; b is 0; orb is 1 and R⁶ is 3′-chloro, 3′-methyl, or 2′-methoxy; or b is 2 and R⁶is 2′-fluoro-5′-chloro, 2′,5′-dichloro, 2′-methyl-5′-chloro, or3′-chloro-5′-hydroxy; R²⁰ is —C₁₋₆alkyl; R²¹ is H; R²² is selected fromH and —C₁₋₆alkyl; and R²³ is selected from —C₁₋₆alkyl, —(CH₂)₂OCH₃, and—C₃₋₇cycloalkyl; or R²² and R²³ are taken together to form azetidine,pyrrolidine, or piperidine, all optionally substituted with —OH or—CONH₂; R²⁴ is phenyl substituted with halo or —OCH₃; R³⁵ is H; themethylene linker on the biphenyl is optionally substituted with 2 methylgroups; and R⁷ is as defined for formula I.

A particular group of compounds of formula I are those disclosed in U.S.Provisional Application No. 61/423,180, filed on Dec. 15, 2010. Thisgroup includes compounds of formula II:

where: R¹ is selected from —OR⁷ and —NR⁸R⁹; R⁷ is selected from H;—C₁₋₆alkyl; —C₁₋₃alkylene-C₆₋₁₀aryl; —C₁₋₃alkylene-C₁₋₉heteroaryl;—C₃₋₇cycloalkyl; —(CH₂)₂OCH₃; —C₁₋₆alkylene-OC(O)R¹⁰; —CH₂-pyridine;—CH₂-pyrrolidine; —C₀₋₆alkylenemorpholine; —C₁₋₆alkylene-SO₂—C₁₋₆alkyl;

where R¹⁰ is selected from —C₁₋₆alkyl, —O—C₁₋₆alkyl, —C₃₋₇cycloalkyl,—O—C₃₋₇cycloalkyl, phenyl, —O-phenyl, —NR¹²R¹³, and —CH(NH₂)CH₂COOCH₃;and R¹² and R¹³ are independently selected from H, —C₁₋₆alkyl, andbenzyl, or R¹² and R¹³ are taken together as —(CH₂)₃₋₆—; R⁸ is selectedfrom H; —OH; —OC(O)R¹⁴; —CH₂COOH; —O-benzyl; pyridyl; and —OC(S)NR¹⁵R¹⁶;where R¹⁴ is selected from H, —C₁₋₆alkyl, —C₆₋₁₀aryl, —OCH₂—C₆₋₁₀aryl,—CH₂O—C₆₋₁₀aryl, and —NR¹⁵R¹⁶; and R¹⁵ and R¹⁶ are independentlyselected from H and —C₁₋₄alkyl; R⁹ is selected from H; —C₁₋₆alkyl; and—C(O)R¹⁷; where R¹⁷ is selected from H; —C₁₋₆alkyl; —C₃₋₇cycloalkyl;—C₆₋₁₀aryl; and —C₁₋₉heteroaryl; R² is H or is taken together with R¹ toform —OCHR¹⁸R¹⁹— or —NHC(O)—; where R¹⁸ and R¹⁹ are independentlyselected from H, —C₁₋₆alkyl, and —O—C₃₋₇cycloalkyl, or R¹⁸ and R¹⁹ aretaken together to form ═O; X is a —C₁₋₉heteroaryl or a partiallyunsaturated —C₃₋₅heterocycle; R³ is absent or is selected from H; halo;—C₀₋₅alkylene-OH; —NH₂; —C₁₋₆alkyl; —C₃₋₇cycloalkyl;—C₀₋₁alkylene-O—C₁₋₆alkyl; —C(O)R²⁰; —C₀₋₁alkylene-C(O)OR²¹;—C(O)NR²²R²³; —NHC(O)R²⁴; phenyl optionally substituted with one groupselected from halo, —CF₃, —OCH₃, —NHC(O)CH₃, and phenyl; napthyl;pyridine; pyrazine; pyrazole optionally substituted with methyl;thiophene optionally substituted with methyl; and furan; and R³, whenpresent, is attached to a carbon atom; R²⁰ is selected from H and—C₁₋₆alkyl; R²¹ is selected from H; —C₁₋₆alkyl; —C₁₋₃alkylene-C₆₋₁₀aryl;—C₁₋₃alkylene-C₁₋₉heteroaryl; —C₃₋₇cycloalkyl; —(CH₂)₂OCH₃;—C₁₋₆alkylene-OC(O)R²⁵; —CH₂-pyridine; —CH₂-pyrrolidine;—C₀₋₆alkylenemorpholine; —C₁₋₆alkylene-SO₂—C₁₋₆alkyl;

where R²⁵ is selected from —C₁₋₆alkyl, —O—C₁₋₆alkyl, —C₃₋₇cycloalkyl,—O—C₃₋₇cycloalkyl, phenyl, —O-phenyl, —NR²⁷R²⁸, and —CH(NH₂)CH₂COOCH₃;and R²⁷ and R²⁸ are independently selected from H, —C₁₋₆alkyl, andbenzyl, or R²⁷ and R²⁸ are taken together as —(CH₂)₃₋₆—; R²² and R²³ areindependently selected from H; —C₁₋₆alkyl; —CH₂COOH; —(CH₂)₂OH;—(CH₂)₂OCH₃; —(CH₂)₂SO₂NH₂; —(CH₂)₂N(CH₃)₂; —C₃₋₇cycloalkyl; and—(CH₂)₂-imidazole; or R²² and R²³ are taken together to form a saturatedor partially unsaturated —C₃₋₅heterocycle optionally substituted with—OH, —COOH, or —CONH₂; and optionally containing an oxygen atom in thering; R²⁴ is selected from —C₁₋₆alkyl; —O—C₁₋₆alkyl; —CH₂—O—C₁₋₆alkyl;phenyl substituted with —OCH₃; and pyridine; R⁴ is selected from H;—C₁₋₆alkyl; phenyl or benzyl substituted with one or more groupsselected from halo, —COOH, —OCH₃, —OCF₃, and —SCF₃; and R⁴ is attachedto a carbon or nitrogen atom; a is 0 or 1; R⁵ is halo or —CF₃; and b is0 or 1; R⁶ is halo; or a pharmaceutically acceptable salt thereof.

In addition, particular compounds of formula I that are of interestinclude those set forth in the Examples below, as well aspharmaceutically acceptable salts thereof.

General Synthetic Procedures

Compounds of the invention can be prepared from readily availablestarting materials using the following general methods, the proceduresset forth in the Examples, or by using other methods, reagents, andstarting materials that are known to those of ordinary skill in the art.Although the following procedures may illustrate a particular embodimentof the invention, it is understood that other embodiments of theinvention can be similarly prepared using the same or similar methods orby using other methods, reagents and starting materials known to thoseof ordinary skill in the art. It will also be appreciated that wheretypical or preferred process conditions (for example, reactiontemperatures, times, mole ratios of reactants, solvents, pressures,etc.) are given, other process conditions can also be used unlessotherwise stated. In some instances, reactions were conducted at roomtemperature and no actual temperature measurement was taken. It isunderstood that room temperature can be taken to mean a temperaturewithin the range commonly associated with the ambient temperature in alaboratory environment, and will typically be in the range of about 18°C. to about 30° C. In other instances, reactions were conducted at roomtemperature and the temperature was actually measured and recorded.While optimum reaction conditions will typically vary depending onvarious reaction parameters such as the particular reactants, solventsand quantities used, those of ordinary skill in the art can readilydetermine suitable reaction conditions using routine optimizationprocedures.

Additionally, as will be apparent to those skilled in the art,conventional protecting groups may be necessary or desired to preventcertain functional groups from undergoing undesired reactions. Thechoice of a suitable protecting group for a particular functional groupas well as suitable conditions and reagents for protection anddeprotection of such functional groups are well-known in the art.Protecting groups other than those illustrated in the proceduresdescribed herein may be used, if desired. For example, numerousprotecting groups, and their introduction and removal, are described inT. W. Greene and G. M. Wuts, Protecting Groups in Organic Synthesis,Fourth Edition, Wiley, New York, 2006, and references cited therein.

Carboxy-protecting groups are suitable for preventing undesiredreactions at a carboxy group, and examples include, but are not limitedto, methyl, ethyl, t-butyl, benzyl (Bn), p-methoxybenzyl (PMB),9-fluorenylmethyl (Fm), trimethylsilyl (TMS), t-butyldimethylsilyl(TBDMS), diphenylmethyl (benzhydryl, DPM) and the like. Amino-protectinggroups are suitable for preventing undesired reactions at an aminogroup, and examples include, but are not limited to, t-butoxycarbonyl(BOC), trityl (Tr), benzyloxycarbonyl (Cbz), 9-fluorenylmethoxycarbonyl(Fmoc), formyl, trimethylsilyl (TMS), t-butyldimethylsilyl (TBDMS), andthe like. Hydroxyl-protecting groups are suitable for preventingundesired reactions at a hydroxyl group, and examples include, but arenot limited to C₁₋₆alkyls, silyl groups including triC₁₋₆alkylsilylgroups, such as trimethylsilyl (TMS), triethylsilyl (TES), andtert-butyldimethylsilyl (TBDMS); esters (acyl groups) includingC₁₋₆alkanoyl groups, such as formyl, acetyl, and pivaloyl, and aromaticacyl groups such as benzoyl; arylmethyl groups such as benzyl (Bn),p-methoxybenzyl (PMB), 9-fluorenylmethyl (Fm), and diphenylmethyl(benzhydryl, DPM); and the like.

Standard deprotection techniques and reagents are used to remove theprotecting groups, and may vary depending upon which group is used. Forexample, sodium or lithium hydroxide is commonly used when thecarboxy-protecting group is methyl, an acid such as TFA or HCl iscommonly used when the carboxy-protecting group is ethyl or t-butyl, andH₂/Pd/C may be used when the carboxy-protecting group is benzyl. A BOCamino-protecting group can be removed using an acidic reagent such asTFA in DCM or HCl in 1,4-dioxane, while a Cbz amino-protecting group canbe removed by employing catalytic hydrogenation conditions such as H₂ (1atm) and 10% Pd/C in an alcoholic solvent (“H₂/Pd/C”). H₂/Pd/C iscommonly used when the hydroxyl-protecting group is benzyl, while NaOHis commonly used when the hydroxyl-protecting group is an acyl group.

Suitable bases for use in these schemes include, by way of illustrationand not limitation, potassium carbonate, calcium carbonate, sodiumcarbonate, triethylamine, pyridine, 1,8-diazabicyclo-[5.4.0]undec-7-ene(DBU), N,N-diisopropylethylamine (DIPEA), 4-methylmorpholine, sodiumhydroxide, potassium hydroxide, potassium t-butoxide, and metalhydrides.

Suitable inert diluents or solvents for use in these schemes include, byway of illustration and not limitation, tetrahydrofuran (THF),acetonitrile (MeCN), N,N-dimethylformamide (DMF), N,N-dimethylacetamide(DMA), dimethyl sulfoxide (DMSO), toluene, dichloromethane (DCM),chloroform (CHCl₃), carbon tetrachloride (CCl₄), 1,4-dioxane, methanol,ethanol, water, and the like.

Suitable carboxylic acid/amine coupling reagents includebenzotriazol-1-yloxytris(dimethylamino)phosphonium hexafluorophosphate(BOP), benzotriazol-1-yloxytripyrrolidinophosphonium hexafluorophosphate(PyBOP), N,N,N′,N′-tetramethyl-O-(7-azabenzotriazol-1-yl)uroniumhexafluorophosphate (HATU), 1,3-dicyclohexylcarbodiimide (DCC),N-(3-dimethylaminopropyl)-N′-ethylcarbodiimide (EDCI),carbonyldiimidazole (CDI), 1-hydroxybenzotriazole (HOBt), and the like.Coupling reactions are conducted in an inert diluent in the presence ofa base such as DIPEA, and are performed under conventional amidebond-forming conditions.

All reactions are typically conducted at a temperature within the rangeof about −78 C to 100° C., for example at room temperature. Reactionsmay be monitored by use of thin layer chromatography (TLC), highperformance liquid chromatography (HPLC), and/or LCMS until completion.Reactions may be complete in minutes, or may take hours, typically from1-2 hours and up to 48 hours. Upon completion, the resulting mixture orreaction product may be further treated in order to obtain the desiredproduct. For example, the resulting mixture or reaction product may besubjected to one or more of the following procedures: concentrating orpartitioning (for example, between EtOAc and water or between 5% THF inEtOAc and 1M phosphoric acid); extraction (for example, with EtOAc,CHCl₃, DCM, chloroform); washing (for example, with saturated aqueousNaCl, saturated aqueous NaHCO₃, Na₂CO₃ (5%), CHCl₃ or 1M NaOH); drying(for example, over MgSO₄, over Na₂SO₄, or in vacuo); filtering;crystallizing (for example, from EtOAc and hexanes); being concentrated(for example, in vacuo); and/or purification (e.g., silica gelchromatography, flash chromatography, preparative HPLC, reversephase-HPLC, or crystallization).

Compounds of formula I, as well as their salts, can be prepared as shownin Scheme I:

The process comprises the step of coupling compound 1 with compound 2,where R¹-R⁶, X, a, and b are as defined for formula I, and P¹ is H or asuitable amino-protecting group, examples of which include,t-butoxycarbonyl, trityl, benzyloxycarbonyl, 9-fluorenylmethoxycarbonyl,formyl, trimethylsilyl, and t-butyldimethylsilyl. When P¹ is an aminoprotecting group, the process further comprises deprotecting thecompound of formula 1, before or in situ with the coupling step.

In instances where R¹ is a group such as —OCH₃ or —OCH₂CH₃, the couplingstep may be followed by a deprotection step to provide a compound offormula I where R¹ is a group such as —OH. Thus, one method of preparingcompounds of the invention involves coupling compounds 1 and 2, with anoptional deprotection step to form a compound of formula I or apharmaceutically acceptable salt thereof.

Methods of preparing compound 1 are described in the Examples. Compound2 is generally commercially available or can be prepared usingprocedures that are known in the art.

Compounds of formula I, as well as their salts, can also be prepared asshown in Scheme II:

In the first step, compound 1 is coupled with compound 3 and compound 3is coupled to compound 4, where Y and Z react in situ to form the R³moiety. For example, when R³ is —C(O)NR²²R²³, Y is —COOH and Z isHNR²²R²³. Alternately, compound 3 is first coupled to compound 4, andthe resulting compound is then coupled with compound 1. As with SchemeI, in instances where R¹ is a group such as —OCH₃ or —OCH₂CH₃, thecoupling step may be followed by a deprotection step to provide acompound of formula I where R¹ is a group such as —OH. Thus, one methodof preparing compounds of the invention involves coupling compounds 1, 2and 3, with an optional deprotection step to form a compound of formulaI or a pharmaceutically acceptable salt thereof.

Compounds 3 and 4 are generally commercially available or can beprepared using procedures that are known in the art.

Compounds of formula I, as well as their salts, can also be prepared asshown in Scheme III: {Based on Example 9}

Again, as with Schemes I and II, this is a standard coupling reactionbetween a compound of formula I, where R¹ is —OH and compound 5, toyield a compound of formula I, where R is —NR⁸R⁹.

Certain intermediates described herein are believed to be novel andaccordingly, such compounds are provided as further aspects of theinvention including, for example, the compounds of formula 1 or a saltthereof:

where P¹ is H or an amino-protecting group selected fromt-butoxycarbonyl, trityl, benzyloxycarbonyl, 9-fluorenylmethoxycarbonyl,formyl, trimethylsilyl, and t-butyldimethylsilyl; and R¹, R², R⁵, R⁶, aand b are as defined for formula I. Another intermediate of theinvention has formula 6 or a salt thereof:

where R^(1P) is selected from —O—P³, —NHP², and —NH(O—P⁴); where P² isan amino-protecting group selected from t-butoxycarbonyl, trityl,benzyloxycarbonyl, 9-fluorenylmethoxycarbonyl, formyl, trimethylsilyl,and t-butyldimethylsilyl; P³ is a carboxy-protecting group selected frommethyl, ethyl, t-butyl, benzyl, p-methoxybenzyl, 9-fluorenylmethyl,trimethylsilyl, t-butyldimethylsilyl, and diphenylmethyl; P⁴ is ahydroxyl-protecting group selected from —C₁₋₆alkyl, triC₁₋₆alkylsilyl,—C₁₋₆alkanoyl, benzoyl, benzyl, p-methoxybenzyl, 9-fluorenylmethyl, anddiphenylmethyl; and R², R³, R⁴, R⁵, R⁶, a, b, and X are as defined forformula I. Another intermediate of the invention has formula 7 or a saltthereof:

where R^(3P) is selected from —C₀₋₅alkylene-O—P⁴, —C₀₋₁alkylene-COO—P³,and phenyl substituted with —O—P⁴; P³ is a carboxy-protecting groupselected from methyl, ethyl, t-butyl, benzyl, p-methoxybenzyl,9-fluorenylmethyl, trimethylsilyl, t-butyldimethylsilyl, anddiphenylmethyl; P⁴ is a hydroxyl-protecting group selected from—C₁₋₆alkyl, triC₁₋₆alkylsilyl, —C₁₋₆alkanoyl, benzoyl, benzyl,p-methoxybenzyl, 9-fluorenylmethyl, and diphenylmethyl; and R¹, R², R⁴,R⁵, R⁶, a, b, and X are as defined for formula I. Still anotherintermediate of the invention has formula 8 or a salt thereof:

where R^(4P) is selected from —O—P⁴; —C₁₋₂alkylene-COO—P³; and phenyl orbenzyl substituted with —COO—P³; P³ is a carboxy-protecting groupselected from methyl, ethyl, t-butyl, benzyl, p-methoxybenzyl,9-fluorenylmethyl, trimethylsilyl, t-butyldimethylsilyl, anddiphenylmethyl; P⁴ is a hydroxyl-protecting group selected from—C₁₋₆alkyl, triC₁₋₆alkylsilyl, —C₁₋₆alkanoyl, benzoyl, benzyl,p-methoxybenzyl, 9-fluorenylmethyl, and diphenylmethyl; and R¹, R², R³,R⁵, R⁶, a, b, and X are as defined for formula I. Yet anotherintermediate of the invention has formula 9 or a salt thereof:

where R^(3P) is selected from —C₀₋₅alkylene-O—P⁴, —C₀₋₁alkylene-COO—P³,and phenyl substituted with —O—P⁴; R^(4P) is selected from —O—P⁴;—C₁₋₂alkylene-COO—P³; and phenyl or benzyl substituted with —COO—P³; P³is a carboxy-protecting group selected from methyl, ethyl, t-butyl,benzyl, p-methoxybenzyl, 9-fluorenylmethyl, trimethylsilyl,t-butyldimethylsilyl, and diphenylmethyl; P⁴ is a hydroxyl-protectinggroup selected from —C₁₋₆alkyl, triC₁₋₆alkylsilyl, —C₁₋₆alkanoyl,benzoyl, benzyl, p-methoxybenzyl, 9-fluorenylmethyl, and diphenylmethyl;and R¹, R², R⁵, R⁶, a, b, and X are as defined for formula I. Thus,another method of preparing compounds of the invention involvesdeprotecting a compound of formula 1, 6, 7, 8, 9, or a salt thereof.

Further details regarding specific reaction conditions and otherprocedures for preparing representative compounds of the invention orintermediates thereof are described in the Examples set forth below.

Utility

Compounds of the invention possess neprilysin (NEP) inhibition activity,that is, the compounds are able to inhibit enzyme-catalytic activity. Inanother embodiment, the compounds do not exhibit significant inhibitoryactivity of the angiotensin-converting enzyme. One measure of theability of a compound to inhibit NEP activity is the inhibition constant(pK_(i)). The pK_(i) value is the negative logarithm to base 10 of thedissociation constant (K_(i)), which is typically reported in molarunits. Compounds of the invention of particular interest are thosehaving a pK_(i) at NEP greater than or equal to 6.0, particularly thosehaving a pK_(i) greater than or equal to 7.0, and even more particularlythose having a pK_(i) greater than or equal to 8.0. In one embodiment,compounds of interest have a pK_(i) in the range of 6.0-6.9; in anotherembodiment, compounds of interest have a pK_(i) in the range of 7.0-7.9;in yet another embodiment, compounds of interest have a pK_(i) in therange of 8.0-8.9; and in still another embodiment, compounds of interesthave a pK_(i) in the range of greater than or equal to 9.0. Such valuescan be determined by techniques that are well known in the art, as wellas in the assays described herein.

Another measure of the ability of a compound to inhibit NEP activity isthe apparent inhibition constant (IC₅₀), which is the molarconcentration of compound that results in half-maximal inhibition ofsubstrate conversion by the NEP enzyme. The pIC₅₀ value is the negativelogarithm to base 10 of the IC₅₀. Compounds of the invention that are ofparticular interest, include those that exhibit a pIC₅₀ for NEP greaterthan or equal to about 5.0. Compounds of interest also include thosehaving a pIC₅₀ for NEP≥about 6.0 or a pIC₅₀ for NEP≥about 7.0. Inanother embodiment, compounds of interest have a pIC₅₀ for NEP withinthe range of about 7.0-11.0; and in another embodiment, within the rangeof about 8.0-11.0, such as within the range of about 8.0-10.0.

It is noted that in some cases, compounds of the invention may possessweak NEP inhibition activity. In such cases, those of skill in the artwill recognize that these compounds still have utility as researchtools.

Exemplary assays to determine properties of compounds of the invention,such as the NEP inhibiting activity, are described in the Examples andinclude by way of illustration and not limitation, assays that measureNEP inhibition (described in Assay 1). Useful secondary assays includeassays to measure ACE inhibition (also described in Assay 1) andaminopeptidase P (APP) inhibition (described in Sulpizio et al. (2005)JPET 315:1306-1313). A pharmacodynamic assay to assess the in vivoinhibitory potencies for ACE and NEP in anesthetized rats is describedin Assay 2 (see also Seymour et al. (1985) Hypertension 7(SupplI):I-35-I-42 and Wigle et al. (1992) Can. J. Physiol. Pharmacol.70:1525-1528), where ACE inhibition is measured as the percentinhibition of the angiotensin I pressor response and NEP inhibition ismeasured as increased urinary cyclic guanosine 3′, 5′-monophosphate(cGMP) output.

There are many in vivo assays that can be used to ascertain furtherutilities of the compounds of the invention. The conscious spontaneouslyhypertensive rat (SHR) model is a renin dependent hypertension model,and is described in Assay 3. See also Intengan et al. (1999) Circulation100(22):2267-2275 and Badyal et al. (2003) Indian Journal ofPharmacology 35:349-362. The conscious desoxycorticosterone acetate-salt(DOCA-salt) rat model is a volume dependent hypertension model that isuseful for measuring NEP activity, and is described in Assay 4. See alsoTrapani et al. (1989) J. Cardiovasc. Pharmacol. 14:419-424, Intengan etal. (1999) Hypertension 34(4):907-913, and Badyal et al. (2003) supra).The DOCA-salt model is particularly useful for evaluating the ability ofa test compound to reduce blood pressure as well as to measure a testcompound's ability to prevent or delay a rise in blood pressure. TheDahl salt-sensitive (DSS) hypertensive rat model is a model ofhypertension that is sensitive to dietary salt (NaCl), and is describedin Assay 5. See also Rapp (1982) Hypertension 4:753-763. The ratmonocrotaline model of pulmonary arterial hypertension described, forexample, in Kato et al. (2008) J. Cardiovasc. Pharmacol. 51(1): 18-23,is a reliable predictor of clinical efficacy for the treatment ofpulmonary arterial hypertension. Heart failure animal models include theDSS rat model for heart failure and the aorto-caval fistula model (AVshunt), the latter of which is described, for example, in Norling et al.(1996) J. Amer. Soc. Nephrol. 7:1038-1044. Other animal models, such asthe hot plate, tail-flick and formalin tests, can be used to measure theanalgesic properties of compounds of the invention, as well as thespinal nerve ligation (SNL) model of neuropathic pain. See, for example,Malmberg et al. (1999) Current Protocols in Neuroscience 8.9.1-8.9.15.

Compounds of the invention are expected to inhibit the NEP enzyme in anyof the assays listed above, or assays of a similar nature. Thus, theaforementioned assays are useful in determining the therapeutic utilityof compounds of the invention, for example, their utility asantihypertensive agents or antidiarrheal agents. Other properties andutilities of compounds of the invention can be demonstrated using otherin vitro and in vivo assays well-known to those skilled in the art.Compounds of formula I may be active drugs as well as prodrugs. Thus,when discussing the activity of compounds of the invention, it isunderstood that any such prodrugs may not exhibit the expected activityin an assay, but are expected to exhibit the desired activity oncemetabolized.

Compounds of the invention are expected to be useful for the treatmentand/or prevention of medical conditions responsive to NEP inhibition.Thus it is expected that patients suffering from a disease or disorderthat is treated by inhibiting the NEP enzyme or by increasing the levelsof its peptide substrates, can be treated by administering atherapeutically effective amount of a compound of the invention. Forexample, by inhibiting NEP, the compounds are expected to potentiate thebiological effects of endogenous peptides that are metabolized by NEP,such as the natriuretic peptides, bombesin, bradykinins, calcitonin,endothelins, enkephalins, neurotensin, substance P and vasoactiveintestinal peptide. Thus, these compounds are expected to have otherphysiological actions, for example, on the renal, central nervous,reproductive and gastrointestinal systems.

In one embodiment of the invention, patients suffering from a disease ordisorder that is treated by inhibiting the NEP enzyme, are treated byadministering a compound of the invention that is in its active form,i.e., a compound of formula I where R¹ is selected from —OR⁷ and —NR⁸R⁹,R⁷ is H, R⁸ is H or —OH, R⁹ is H, and R²-R⁶, a, b, and X are as definedfor formula I.

In another embodiment, patients are treated by administering a compoundthat is metabolized in vitro to form a compound of formula I where R¹ isselected from —OR⁷ and —NR⁸R⁹, R⁷ is H, R⁸ is H or —OH, R⁹ is H, andR²-R⁶, a, b, and X are as defined for formula I. In an exemplaryembodiment, patients are treated by administering a compound that ismetabolized in vitro to form a compound of formula III where R¹ is —OR⁷and R⁷ is H.

In another embodiment, patients are treated by administering a compoundof the invention that is in its prodrug form at the R¹ group, i.e., acompound of formula I where:

R¹ is —OR⁷; and R⁷ is selected from —C₁₋₈alkyl, —C₁₋₃alkylene-C₆₋₁₀aryl,—C₁₋₃alkylene-C₁₋₉heteroaryl, —C₃₋₇cycloalkyl, —[(CH₂)₂O]₁₋₃CH₃,—C₁₋₆alkylene-OC(O)R¹⁰, —C₁₋₆alkylene-NR¹²R¹³, —C₁₋₆alkylene-C(O)R³¹,—C₀₋₆alkylenemorpholinyl, —C₁₋₆alkylene-SO₂—C₁₋₆alkyl,

R¹ is —NR⁸R⁹; R⁸ is selected from —OC(O)R¹⁴, —CH₂COOH, —O-benzyl,pyridyl, and —OC(S)NR¹⁵R¹⁶; and R⁹ is H; or

R¹ is —NR⁸R⁹; R⁸ is selected from —OC(O)R¹⁴, —CH₂COOH, —O-benzyl,pyridyl, and —OC(S)NR¹⁵R¹⁶; and R⁹ is —C₁₋₆alkyl or —C(O)R¹⁷;

R¹ is —NR⁸R⁹; R⁸ is selected from H or —OH; and R⁹ is selected from—C₁₋₆alkyl, and —C(O)R¹⁷;

R¹ is —OR⁷ and R² is taken together with R⁷ to form —CR¹⁸R¹⁹—; or

R¹ is —NR⁸R⁹ and R² is taken together with R⁸ to form —C(O)—; and R¹⁰,R¹²-R¹⁷, R³¹, R³², R³-R⁶, a, b, and X are as defined for formula I. Inan exemplary embodiment, patients are treated by administering acompound of the invention that is in its prodrug form at the R¹ groupand has formula III.

Cardiovascular Diseases

By potentiating the effects of vasoactive peptides like the natriureticpeptides and bradykinin, compounds of the invention are expected to findutility in treating and/or preventing medical conditions such ascardiovascular diseases. See, for example, Roques et al. (1993)Pharmacol. Rev. 45:87-146 and Dempsey et al. (2009) Amer. J. ofPathology 174(3):782-796. Cardiovascular diseases of particular interestinclude hypertension and heart failure. Hypertension includes, by way ofillustration and not limitation: primary hypertension, which is alsoreferred to as essential hypertension or idiopathic hypertension;secondary hypertension; hypertension with accompanying renal disease;severe hypertension with or without accompanying renal disease;pulmonary hypertension, including pulmonary arterial hypertension; andresistant hypertension. Heart failure includes, by way of illustrationand not limitation: congestive heart failure; acute heart failure;chronic heart failure, for example with reduced left ventricularejection fraction (also referred to as systolic heart failure) or withpreserved left ventricular ejection fraction (also referred to asdiastolic heart failure); and acute and chronic decompensated heartfailure, with or without accompanying renal disease. Thus, oneembodiment of the invention relates to a method for treatinghypertension, particularly primary hypertension or pulmonary arterialhypertension, comprising administering to a patient a therapeuticallyeffective amount of a compound of the invention.

For treatment of primary hypertension, the therapeutically effectiveamount is typically the amount that is sufficient to lower the patient'sblood pressure. This would include both mild-to-moderate hypertensionand severe hypertension. When used to treat hypertension, the compoundmay be administered in combination with other therapeutic agents such asaldosterone antagonists, aldosterone synthase inhibitors,angiotensin-converting enzyme inhibitors and dual-actingangiotensin-converting enzyme/neprilysin inhibitors,angiotensin-converting enzyme 2 (ACE2) activators and stimulators,angiotensin-II vaccines, anti-diabetic agents, anti-lipid agents,anti-thrombotic agents, AT₁ receptor antagonists and dual-acting AT₁receptor antagonist/neprilysin inhibitors, β₁-adrenergic receptorantagonists, dual-acting β-adrenergic receptor antagonist/α₁-receptorantagonists, calcium channel blockers, diuretics, endothelin receptorantagonists, endothelin converting enzyme inhibitors, neprilysininhibitors, natriuretic peptides and their analogs, natriuretic peptideclearance receptor antagonists, nitric oxide donors, non-steroidalanti-inflammatory agents, phosphodiesterase inhibitors (specificallyPDE-V inhibitors), prostaglandin receptor agonists, renin inhibitors,soluble guanylate cyclase stimulators and activators, and combinationsthereof. In one particular embodiment of the invention, a compound ofthe invention is combined with an AT₁ receptor antagonist, a calciumchannel blocker, a diuretic, or a combination thereof, and used to treatprimary hypertension. In another particular embodiment of the invention,a compound of the invention is combined with an AT₁ receptor antagonist,and used to treat hypertension with accompanying renal disease. Whenused to treat resistant hypertension, the compound may be administeredin combination with other therapeutic agents such as aldosteronesynthase inhibitors.

For treatment of pulmonary arterial hypertension, the therapeuticallyeffective amount is typically the amount that is sufficient to lower thepulmonary vascular resistance. Other goals of therapy are to improve apatient's exercise capacity. For example, in a clinical setting, thetherapeutically effective amount can be the amount that improves apatient's ability to walk comfortably for a period of 6 minutes(covering a distance of approximately 20-40 meters). When used to treatpulmonary arterial hypertension the compound may be administered incombination with other therapeutic agents such as α-adrenergic receptorantagonists, β₁-adrenergic receptor antagonists, β₂-adrenergic receptoragonists, angiotensin-converting enzyme inhibitors, anticoagulants,calcium channel blockers, diuretics, endothelin receptor antagonists,PDE-V inhibitors, prostaglandin analogs, selective serotonin reuptakeinhibitors, and combinations thereof. In one particular embodiment ofthe invention, a compound of the invention is combined with a PDE-Vinhibitor or a selective serotonin reuptake inhibitor and used to treatpulmonary arterial hypertension.

Another embodiment of the invention relates to a method for treatingheart failure, in particular congestive heart failure (including bothsystolic and diastolic congestive heart failure), comprisingadministering to a patient a therapeutically effective amount of acompound of the invention. Typically, the therapeutically effectiveamount is the amount that is sufficient to lower blood pressure and/orimprove renal functions. In a clinical setting, the therapeuticallyeffective amount can be the amount that is sufficient to improve cardiachemodynamics, like for instance reduction in wedge pressure, rightatrial pressure, filling pressure, and vascular resistance. In oneembodiment, the compound is administered as an intravenous dosage form.When used to treat heart failure, the compound may be administered incombination with other therapeutic agents such as adenosine receptorantagonists, advanced glycation end product breakers, aldosteroneantagonists, AT₁ receptor antagonists, β₁-adrenergic receptorantagonists, dual-acting β-adrenergic receptor antagonist/α₁-receptorantagonists, chymase inhibitors, digoxin, diuretics, endothelinconverting enzyme (ECE) inhibitors, endothelin receptor antagonists,natriuretic peptides and their analogs, natriuretic peptide clearancereceptor antagonists, nitric oxide donors, prostaglandin analogs, PDE-Vinhibitors, soluble guanylate cyclase activators and stimulators, andvasopressin receptor antagonists. In one particular embodiment of theinvention, a compound of the invention is combined with an aldosteroneantagonist, a β₁-adrenergic receptor antagonist, an AT₁ receptorantagonist, or a diuretic, and used to treat congestive heart failure.

Diarrhea

As NEP inhibitors, compounds of the invention are expected to inhibitthe degradation of endogenous enkephalins and thus such compounds mayalso find utility for the treatment of diarrhea, including infectiousand secretory/watery diarrhea. See, for example, Baumer et al. (1992)Gut 33:753-758; Farthing (2006) Digestive Diseases 24:47-58; andMarçais-Collado (1987) Eur. J. Pharmacol. 144(2):125-132. When used totreat diarrhea, compounds of the invention may be combined with one ormore additional antidiarrheal agents.

Renal Diseases

By potentiating the effects of vasoactive peptides like the natriureticpeptides and bradykinin, compounds of the invention are expected toenhance renal function (see Chen et al. (1999) Circulation100:2443-2448; Lipkin et al. (1997) Kidney Int. 52:792-801; and Dussauleet al. (1993) Clin. Sci. 84:31-39) and find utility in treating and/orpreventing renal diseases. Renal diseases of particular interest includediabetic nephropathy, chronic kidney disease, proteinuria, andparticularly acute kidney injury or acute renal failure (see Sharkovskaet al. (2011) Clin. Lab. 57:507-515 and Newaz et al. (2010) RenalFailure 32:384-390). When used to treat renal disease, the compound maybe administered in combination with other therapeutic agents such asangiotensin-converting enzyme inhibitors, AT₁ receptor antagonists, anddiuretics.

Preventative Therapy

By potentiating the effects of the natriuretic peptides, compounds ofthe invention are also expected to be useful in preventative therapy,due to the antihypertrophic and antifibrotic effects of the natriureticpeptides (see Potter et al. (2009) Handbook of Experimental Pharmacology191:341-366), for example in preventing the progression of cardiacinsufficiency after myocardial infarction, preventing arterialrestenosis after angioplasty, preventing thickening of blood vesselwalls after vascular operations, preventing atherosclerosis, andpreventing diabetic angiopathy.

Glaucoma

By potentiating the effects of the natriuretic peptides, compounds ofthe invention are expected to be useful to treat glaucoma. See, forexample, Diestelhorst et al. (1989) International Ophthalmology12:99-101. When used to treat glaucoma, compounds of the invention maybe combined with one or more additional antiglaucoma agents.

Pain Relief

As NEP inhibitors, compounds of the invention are expected to inhibitthe degradation of endogenous enkephalins and thus such compounds mayalso find utility as analgesics. See, for example, Roques et al. (1980)Nature 288:286-288 and Thanawala et al. (2008) Current Drug Targets9:887-894. When used to treat pain, the compounds of the invention maybe combined with one or more additional antinociceptive drugs such asaminopeptidase N or dipeptidyl peptidase III inhibitors, non-steroidalanti-inflammatory agents, monoamine reuptake inhibitors, musclerelaxants, NMDA receptor antagonists, opioid receptor agonists,5-HT_(1D) serotonin receptor agonists, and tricyclic antidepressants.

Other Utilities

Due to their NEP inhibition properties, compounds of the invention arealso expected to be useful as antitussive agents, as well as findutility in the treatment of portal hypertension associated with livercirrhosis (see Sansoe et al. (2005) J. Hepatol. 43:791-798), cancer (seeVesely (2005) J. Investigative Med. 53:360-365), depression (see Nobleet al. (2007) Exp. Opin. Ther. Targets 11:145-159), menstrual disorders,preterm labor, pre-eclampsia, endometriosis, reproductive disorders (forexample, male and female infertility, polycystic ovarian syndrome,implantation failure), and male and female sexual dysfunction, includingmale erectile dysfunction and female sexual arousal disorder. Morespecifically, the compounds of the invention are expected to be usefulin treating female sexual dysfunction (see Pryde et al. (2006) J. Med.Chem. 49:4409-4424), which is often defined as a female patient'sdifficulty or inability to find satisfaction in sexual expression. Thiscovers a variety of diverse female sexual disorders including, by way ofillustration and not limitation, hypoactive sexual desire disorder,sexual arousal disorder, orgasmic disorder and sexual pain disorder.When used to treat such disorders, especially female sexual dysfunction,compounds of the invention may be combined with one or more of thefollowing secondary agents: PDE-V inhibitors, dopamine agonists,estrogen receptor agonists and/or antagonists, androgens, and estrogens.Due to their NEP inhibition properties, compounds of the invention arealso expected to have anti-inflammatory properties, and are expected tohave utility as such, particularly when used in combination withstatins.

Recent studies suggest that NEP plays a role in regulating nervefunction in insulin-deficient diabetes and diet induced obesity. Coppeyet al. (2011) Neuropharmacology 60:259-266. Therefore, due to their NEPinhibition properties, compounds of the invention are also expected tobe useful in providing protection from nerve impairment caused bydiabetes or diet induced obesity.

The amount of the compound of the invention administered per dose or thetotal amount administered per day may be predetermined or it may bedetermined on an individual patient basis by taking into considerationnumerous factors, including the nature and severity of the patient'scondition, the condition being treated, the age, weight, and generalhealth of the patient, the tolerance of the patient to the active agent,the route of administration, pharmacological considerations such as theactivity, efficacy, pharmacokinetics and toxicology profiles of thecompound and any secondary agents being administered, and the like.Treatment of a patient suffering from a disease or medical condition(such as hypertension) can begin with a predetermined dosage or a dosagedetermined by the treating physician, and will continue for a period oftime necessary to prevent, ameliorate, suppress, or alleviate thesymptoms of the disease or medical condition. Patients undergoing suchtreatment will typically be monitored on a routine basis to determinethe effectiveness of therapy. For example, in treating hypertension,blood pressure measurements may be used to determine the effectivenessof treatment. Similar indicators for other diseases and conditionsdescribed herein, are well known and are readily available to thetreating physician. Continuous monitoring by the physician will insurethat the optimal amount of the compound of the invention will beadministered at any given time, as well as facilitating thedetermination of the duration of treatment. This is of particular valuewhen secondary agents are also being administered, as their selection,dosage, and duration of therapy may also require adjustment. In thisway, the treatment regimen and dosing schedule can be adjusted over thecourse of therapy so that the lowest amount of active agent thatexhibits the desired effectiveness is administered and, further, thatadministration is continued only so long as is necessary to successfullytreat the disease or medical condition.

Research Tools

Since compounds of the invention possess NEP enzyme inhibition activity,such compounds are also useful as research tools for investigating orstudying biological systems or samples having a NEP enzyme, for exampleto study diseases where the NEP enzyme or its peptide substrates plays arole. Any suitable biological system or sample having a NEP enzyme maybe employed in such studies which may be conducted either in vitro or invivo. Representative biological systems or samples suitable for suchstudies include, but are not limited to, cells, cellular extracts,plasma membranes, tissue samples, isolated organs, mammals (such asmice, rats, guinea pigs, rabbits, dogs, pigs, humans, and so forth), andthe like, with mammals being of particular interest. In one particularembodiment of the invention, NEP enzyme activity in a mammal isinhibited by administering a NEP-inhibiting amount of a compound of theinvention. Compounds of the invention can also be used as research toolsby conducting biological assays using such compounds.

When used as a research tool, a biological system or sample comprising aNEP enzyme is typically contacted with a NEP enzyme-inhibiting amount ofa compound of the invention. After the biological system or sample isexposed to the compound, the effects of inhibiting the NEP enzyme aredetermined using conventional procedures and equipment, such as bymeasuring receptor binding in a binding assay or measuringligand-mediated changes in a functional assay. Exposure encompassescontacting cells or tissue with the compound, administering the compoundto a mammal, for example by i.p., p.o, i.v., s.c., or inhaledadministration, and so forth. This determining step can involvemeasuring a response (a quantitative analysis) or can involve making anobservation (a qualitative analysis). Measuring a response involves, forexample, determining the effects of the compound on the biologicalsystem or sample using conventional procedures and equipment, such asenzyme activity assays and measuring enzyme substrate or productmediated changes in functional assays. The assay results can be used todetermine the activity level as well as the amount of compound necessaryto achieve the desired result, that is, a NEP enzyme-inhibiting amount.Typically, the determining step will involve determining the effects ofinhibiting the NEP enzyme.

Additionally, compounds of the invention can be used as research toolsfor evaluating other chemical compounds, and thus are also useful inscreening assays to discover, for example, new compounds havingNEP-inhibiting activity. In this manner, a compound of the invention isused as a standard in an assay to allow comparison of the resultsobtained with a test compound and with compounds of the invention toidentify those test compounds that have about equal or superioractivity, if any. For example, pK_(i) data for a test compound or agroup of test compounds is compared to the pK_(i) data for a compound ofthe invention to identify those test compounds that have the desiredproperties, for example, test compounds having a pK_(i) value aboutequal or superior to a compound of the invention, if any. This aspect ofthe invention includes, as separate embodiments, both the generation ofcomparison data (using the appropriate assays) and the analysis of testdata to identify test compounds of interest. Thus, a test compound canbe evaluated in a biological assay, by a method comprising the steps of:(a) conducting a biological assay with a test compound to provide afirst assay value; (b) conducting the biological assay with a compoundof the invention to provide a second assay value; wherein step (a) isconducted either before, after or concurrently with step (b); and (c)comparing the first assay value from step (a) with the second assayvalue from step (b). Exemplary biological assays include a NEP enzymeinhibition assay.

Pharmaceutical Compositions and Formulations

Compounds of the invention are typically administered to a patient inthe form of a pharmaceutical composition or formulation. Suchpharmaceutical compositions may be administered to the patient by anyacceptable route of administration including, but not limited to, oral,rectal, vaginal, nasal, inhaled, topical (including transdermal),ocular, and parenteral modes of administration. Further, the compoundsof the invention may be administered, for example orally, in multipledoses per day (for example, two, three, or four times daily), in asingle daily dose or a single weekly dose. It will be understood thatany form of the compounds of the invention, (that is, free base, freeacid, pharmaceutically acceptable salt, solvate, etc.) that is suitablefor the particular mode of administration can be used in thepharmaceutical compositions discussed herein.

Accordingly, in one embodiment, the invention relates to apharmaceutical composition comprising a pharmaceutically acceptablecarrier and a compound of the invention. The compositions may containother therapeutic and/or formulating agents if desired. When discussingcompositions, the “compound of the invention” may also be referred toherein as the “active agent,” to distinguish it from other components ofthe formulation, such as the carrier. Thus, it is understood that theterm “active agent” includes compounds of formula I as well aspharmaceutically acceptable salts, solvates and prodrugs of thatcompound.

The pharmaceutical compositions of the invention typically contain atherapeutically effective amount of a compound of the invention. Thoseskilled in the art will recognize, however, that a pharmaceuticalcomposition may contain more than a therapeutically effective amount,such as in bulk compositions, or less than a therapeutically effectiveamount, that is, individual unit doses designed for multipleadministration to achieve a therapeutically effective amount. Typically,the composition will contain from about 0.01-95 wt % of active agent,including, from about 0.01-30 wt %, such as from about 0.01-10 wt %,with the actual amount depending upon the formulation itself, the routeof administration, the frequency of dosing, and so forth. In oneembodiment, a composition suitable for an oral dosage form, for example,may contain about 5-70 wt %, or from about 10-60 wt % of active agent.

Any conventional carrier or excipient may be used in the pharmaceuticalcompositions of the invention. The choice of a particular carrier orexcipient, or combinations of carriers or excipients, will depend on themode of administration being used to treat a particular patient or typeof medical condition or disease state. In this regard, the preparationof a suitable composition for a particular mode of administration iswell within the scope of those skilled in the pharmaceutical arts.Additionally, carriers or excipients used in such compositions arecommercially available. By way of further illustration, conventionalformulation techniques are described in Remington: The Science andPractice of Pharmacy, 20^(th) Edition, Lippincott Williams & White,Baltimore, Md. (2000); and H. C. Ansel et al., Pharmaceutical DosageForms and Drug Delivery Systems, 7^(th) Edition, Lippincott Williams &White, Baltimore, Md. (1999).

Representative examples of materials which can serve as pharmaceuticallyacceptable carriers include, but are not limited to, the following:sugars, such as lactose, glucose and sucrose; starches, such as cornstarch and potato starch; cellulose, such as microcrystalline cellulose,and its derivatives, such as sodium carboxymethyl cellulose, ethylcellulose and cellulose acetate; powdered tragacanth; malt; gelatin;talc; excipients, such as cocoa butter and suppository waxes; oils, suchas peanut oil, cottonseed oil, safflower oil, sesame oil, olive oil,corn oil and soybean oil; glycols, such as propylene glycol; polyols,such as glycerin, sorbitol, mannitol and polyethylene glycol; esters,such as ethyl oleate and ethyl laurate; agar; buffering agents, such asmagnesium hydroxide and aluminum hydroxide; alginic acid; pyrogen-freewater; isotonic saline; Ringer's solution; ethyl alcohol; phosphatebuffer solutions; compressed propellant gases, such aschlorofluorocarbons and hydrofluorocarbons; and other non-toxiccompatible substances employed in pharmaceutical compositions.

Pharmaceutical compositions are typically prepared by thoroughly andintimately mixing or blending the active agent with a pharmaceuticallyacceptable carrier and one or more optional ingredients. The resultinguniformly blended mixture may then be shaped or loaded into tablets,capsules, pills, canisters, cartridges, dispensers and the like usingconventional procedures and equipment.

In one embodiment, the pharmaceutical compositions are suitable for oraladministration. Suitable compositions for oral administration may be inthe form of capsules, tablets, pills, lozenges, cachets, dragees,powders, granules; solutions or suspensions in an aqueous or non-aqueousliquid; oil-in-water or water-in-oil liquid emulsions; elixirs orsyrups; and the like; each containing a predetermined amount of theactive agent.

When intended for oral administration in a solid dosage form (capsules,tablets, pills and the like), the composition will typically comprisethe active agent and one or more pharmaceutically acceptable carriers,such as sodium citrate or dicalcium phosphate. Solid dosage forms mayalso comprise: fillers or extenders, such as starches, microcrystallinecellulose, lactose, sucrose, glucose, mannitol, and/or silicic acid;binders, such as carboxymethylcellulose, alginates, gelatin, polyvinylpyrrolidone, sucrose and/or acacia; humectants, such as glycerol;disintegrating agents, such as agar-agar, calcium carbonate, potato ortapioca starch, alginic acid, certain silicates, and/or sodiumcarbonate; solution retarding agents, such as paraffin; absorptionaccelerators, such as quaternary ammonium compounds; wetting agents,such as cetyl alcohol and/or glycerol monostearate; absorbents, such askaolin and/or bentonite clay; lubricants, such as talc, calciumstearate, magnesium stearate, solid polyethylene glycols, sodium laurylsulfate, and/or mixtures thereof; coloring agents; and buffering agents.

Release agents, wetting agents, coating agents, sweetening, flavoringand perfuming agents, preservatives and antioxidants may also be presentin the pharmaceutical compositions. Exemplary coating agents fortablets, capsules, pills and like, include those used for entericcoatings, such as cellulose acetate phthalate, polyvinyl acetatephthalate, hydroxypropyl methylcellulose phthalate, methacrylicacid-methacrylic acid ester copolymers, cellulose acetate trimellitate,carboxymethyl ethyl cellulose, hydroxypropyl methyl cellulose acetatesuccinate, and the like. Examples of pharmaceutically acceptableantioxidants include: water-soluble antioxidants, such as ascorbic acid,cysteine hydrochloride, sodium bisulfate, sodium metabisulfate sodiumsulfite and the like; oil-soluble antioxidants, such as ascorbylpalmitate, butylated hydroxyanisole, butylated hydroxytoluene, lecithin,propyl gallate, alpha-tocopherol, and the like; and metal-chelatingagents, such as citric acid, ethylenediamine tetraacetic acid, sorbitol,tartaric acid, phosphoric acid, and the like.

Compositions may also be formulated to provide slow or controlledrelease of the active agent using, by way of example, hydroxypropylmethyl cellulose in varying proportions or other polymer matrices,liposomes and/or microspheres. In addition, the pharmaceuticalcompositions of the invention may contain opacifying agents and may beformulated so that they release the active agent only, orpreferentially, in a certain portion of the gastrointestinal tract,optionally, in a delayed manner. Examples of embedding compositionswhich can be used include polymeric substances and waxes. The activeagent can also be in micro-encapsulated form, optionally with one ormore of the above-described excipients.

Suitable liquid dosage forms for oral administration include, by way ofillustration, pharmaceutically acceptable emulsions, microemulsions,solutions, suspensions, syrups and elixirs. Liquid dosage formstypically comprise the active agent and an inert diluent, such as, forexample, water or other solvents, solubilizing agents and emulsifiers,such as ethyl alcohol, isopropyl alcohol, ethyl carbonate, ethylacetate, benzyl alcohol, benzyl benzoate, propylene glycol, 1,3-butyleneglycol, oils (for example, cottonseed, groundnut, corn, germ, olive,castor and sesame oils), glycerol, tetrahydrofuryl alcohol, polyethyleneglycols and fatty acid esters of sorbitan, and mixtures thereof.Suspensions may contain suspending agents such as, for example,ethoxylated isostearyl alcohols, polyoxyethylene sorbitol and sorbitanesters, microcrystalline cellulose, aluminium metahydroxide, bentonite,agar-agar and tragacanth, and mixtures thereof.

When intended for oral administration, the pharmaceutical compositionsof the invention may be packaged in a unit dosage form. The term “unitdosage form” refers to a physically discrete unit suitable for dosing apatient, that is, each unit containing a predetermined quantity of theactive agent calculated to produce the desired therapeutic effect eitheralone or in combination with one or more additional units. For example,such unit dosage forms may be capsules, tablets, pills, and the like.

In another embodiment, the compositions of the invention are suitablefor inhaled administration, and will typically be in the form of anaerosol or a powder. Such compositions are generally administered usingwell-known delivery devices, such as a nebulizer, dry powder, ormetered-dose inhaler. Nebulizer devices produce a stream of highvelocity air that causes the composition to spray as a mist that iscarried into a patient's respiratory tract. An exemplary nebulizerformulation comprises the active agent dissolved in a carrier to form asolution, or micronized and combined with a carrier to form a suspensionof micronized particles of respirable size. Dry powder inhalersadminister the active agent as a free-flowing powder that is dispersedin a patient's air-stream during inspiration. An exemplary dry powderformulation comprises the active agent dry-blended with an excipientsuch as lactose, starch, mannitol, dextrose, polylactic acid,polylactide-co-glycolide, and combinations thereof. Metered-doseinhalers discharge a measured amount of the active agent usingcompressed propellant gas. An exemplary metered-dose formulationcomprises a solution or suspension of the active agent in a liquefiedpropellant, such as a chlorofluorocarbon or hydrofluoroalkane. Optionalcomponents of such formulations include co-solvents, such as ethanol orpentane, and surfactants, such as sorbitan trioleate, oleic acid,lecithin, glycerin, and sodium lauryl sulfate. Such compositions aretypically prepared by adding chilled or pressurized hydrofluoroalkane toa suitable container containing the active agent, ethanol (if present)and the surfactant (if present). To prepare a suspension, the activeagent is micronized and then combined with the propellant.Alternatively, a suspension formulation can be prepared by spray dryinga coating of surfactant on micronized particles of the active agent. Theformulation is then loaded into an aerosol canister, which forms aportion of the inhaler.

Compounds of the invention can also be administered parenterally (forexample, by subcutaneous, intravenous, intramuscular, or intraperitonealinjection). For such administration, the active agent is provided in asterile solution, suspension, or emulsion.

Exemplary solvents for preparing such formulations include water,saline, low molecular weight alcohols such as propylene glycol,polyethylene glycol, oils, gelatin, fatty acid esters such as ethyloleate, and the like. Parenteral formulations may also contain one ormore anti-oxidants, solubilizers, stabilizers, preservatives, wettingagents, emulsifiers, and dispersing agents. Surfactants, additionalstabilizing agents or pH-adjusting agents (acids, bases or buffers) andanti-oxidants are particularly useful to provide stability to theformulation, for example, to minimize or avoid hydrolysis of ester andamide linkages that may be present in the compound. These formulationsmay be rendered sterile by use of a sterile injectable medium, asterilizing agent, filtration, irradiation, or heat. In one particularembodiment, the parenteral formulation comprises an aqueous cyclodextrinsolution as the pharmaceutically acceptable carrier. Suitablecyclodextrins include cyclic molecules containing six or moreα-D-glucopyranose units linked at the 1,4 positions by a linkages as inamylase, β-cyclodextrin or cycloheptaamylose. Exemplary cyclodextrinsinclude cyclodextrin derivatives such as hydroxypropyl and sulfobutylether cyclodextrins such as hydroxypropyl-β-cyclodextrin and sulfobutylether β-cyclodextrin. Exemplary buffers for such formulations includecarboxylic acid-based buffers such as citrate, lactate and maleatebuffer solutions.

Compounds of the invention can also be administered transdermally usingknown transdermal delivery systems and excipients. For example, thecompound can be admixed with permeation enhancers, such as propyleneglycol, polyethylene glycol monolaurate, azacycloalkan-2-ones and thelike, and incorporated into a patch or similar delivery system.Additional excipients including gelling agents, emulsifiers and buffers,may be used in such transdermal compositions if desired.

Secondary Agents

The compounds of the invention may be useful as the sole treatment of adisease or may be combined with one or more additional therapeuticagents in order to obtain the desired therapeutic effect. Thus, in oneembodiment, pharmaceutical compositions of the invention contain otherdrugs that are co-administered with a compound of the invention.

For example, the composition may further comprise one or more drugs(also referred to as “secondary agents(s)”). Such therapeutic agents arewell known in the art, and include adenosine receptor antagonists,α-adrenergic receptor antagonists, β₁-adrenergic receptor antagonists,β₂-adrenergic receptor agonists, dual-acting β-adrenergic receptorantagonist/α₁-receptor antagonists, advanced glycation end productbreakers, aldosterone antagonists, aldosterone synthase inhibitors,aminopeptidase N inhibitors, androgens, angiotensin-converting enzymeinhibitors and dual-acting angiotensin-converting enzyme/neprilysininhibitors, angiotensin-converting enzyme 2 activators and stimulators,angiotensin-II vaccines, anticoagulants, anti-diabetic agents,antidiarrheal agents, anti-glaucoma agents, anti-lipid agents,antinociceptive agents, anti-thrombotic agents, AT₁ receptor antagonistsand dual-acting AT₁ receptor antagonist/neprilysin inhibitors andmultifunctional angiotensin receptor blockers, bradykinin receptorantagonists, calcium channel blockers, chymase inhibitors, digoxin,diuretics, dopamine agonists, endothelin converting enzyme inhibitors,endothelin receptor antagonists, HMG-CoA reductase inhibitors,estrogens, estrogen receptor agonists and/or antagonists, monoaminereuptake inhibitors, muscle relaxants, natriuretic peptides and theiranalogs, natriuretic peptide clearance receptor antagonists, neprilysininhibitors, nitric oxide donors, non-steroidal anti-inflammatory agents,N-methyl d-aspartate receptor antagonists, opioid receptor agonists,phosphodiesterase inhibitors, prostaglandin analogs, prostaglandinreceptor agonists, renin inhibitors, selective serotonin reuptakeinhibitors, sodium channel blocker, soluble guanylate cyclasestimulators and activators, tricyclic antidepressants, vasopressinreceptor antagonists, and combinations thereof. Specific examples ofthese agents are detailed herein.

Accordingly, in yet another aspect of the invention, a pharmaceuticalcomposition comprises a compound of the invention, a second activeagent, and a pharmaceutically acceptable carrier. Third, fourth etc.active agents may also be included in the composition. In combinationtherapy, the amount of compound of the invention that is administered,as well as the amount of secondary agents, may be less than the amounttypically administered in monotherapy.

Compounds of the invention may be physically mixed with the secondactive agent to form a composition containing both agents; or each agentmay be present in separate and distinct compositions which areadministered to the patient simultaneously or at separate times. Forexample, a compound of the invention can be combined with a secondactive agent using conventional procedures and equipment to form acombination of active agents comprising a compound of the invention anda second active agent. Additionally, the active agents may be combinedwith a pharmaceutically acceptable carrier to form a pharmaceuticalcomposition comprising a compound of the invention, a second activeagent and a pharmaceutically acceptable carrier. In this embodiment, thecomponents of the composition are typically mixed or blended to create aphysical mixture. The physical mixture is then administered in atherapeutically effective amount using any of the routes describedherein.

Alternatively, the active agents may remain separate and distinct beforeadministration to the patient. In this embodiment, the agents are notphysically mixed together before administration but are administeredsimultaneously or at separate times as separate compositions. Suchcompositions can be packaged separately or may be packaged together in akit. When administered at separate times, the secondary agent willtypically be administered less than 24 hours after administration of thecompound of the invention, ranging anywhere from concurrent withadministration of the compound of the invention to about 24 hourspost-dose. This is also referred to as sequential administration. Thus,a compound of the invention can be orally administered simultaneously orsequentially with another active agent using two tablets, with onetablet for each active agent, where sequential may mean beingadministered immediately after administration of the compound of theinvention or at some predetermined time later (for example, one hourlater or three hours later). It is also contemplated that the secondaryagent may be administered more than 24 hours after administration of thecompound of the invention. Alternatively, the combination may beadministered by different routes of administration, that is, one orallyand the other by inhalation.

In one embodiment, the kit comprises a first dosage form comprising acompound of the invention and at least one additional dosage formcomprising one or more of the secondary agents set forth herein, inquantities sufficient to carry out the methods of the invention. Thefirst dosage form and the second (or third, etc.) dosage form togethercomprise a therapeutically effective amount of active agents for thetreatment or prevention of a disease or medical condition in a patient.

Secondary agent(s), when included, are present in a therapeuticallyeffective amount such that they are typically administered in an amountthat produces a therapeutically beneficial effect when co-administeredwith a compound of the invention. The secondary agent can be in the formof a pharmaceutically acceptable salt, solvate, optically purestereoisomer, and so forth. The secondary agent may also be in the formof a prodrug, for example, a compound having a carboxylic acid groupthat has been esterified. Thus, secondary agents listed herein areintended to include all such forms, and are commercially available orcan be prepared using conventional procedures and reagents.

In one embodiment, compounds of the invention are administered incombination with an adenosine receptor antagonist, representativeexamples of which include, but are not limited to, naxifylline,rolofylline, SLV-320, theophylline, and tonapofylline.

In one embodiment, compounds of the invention are administered incombination with an α-adrenergic receptor antagonist, representativeexamples of which include, but are not limited to, doxazosin, prazosin,tamsulosin, and terazosin.

Compounds of the invention may also be administered in combination witha β₁-adrenergic receptor antagonist (“β₁-blockers”). Representativeβ₁-blockers include, but are not limited to, acebutolol, alprenolol,amosulalol, arotinolol, atenolol, befunolol, betaxolol, bevantolol,bisoprolol, bopindolol, bucindolol, bucumolol, bufetolol, bufuralol,bunitrolol, bupranolol, bubridine, butofilolol, carazolol, carteolol,carvedilol, celiprolol, cetamolol, cloranolol, dilevalol, epanolol,esmolol, indenolol, labetolol, levobunolol, mepindolol, metipranolol,metoprolol such as metoprolol succinate and metoprolol tartrate,moprolol, nadolol, nadoxolol, nebivalol, nipradilol, oxprenolol,penbutolol, perbutolol, pindolol, practolol, pronethalol, propranolol,sotalol, sufinalol, talindol, tertatolol, tilisolol, timolol,toliprolol, xibenolol, and combinations thereof. In one particularembodiment, the β₁-antagonist is selected from atenolol, bisoprolol,metoprolol, propranolol, sotalol, and combinations thereof. Typically,the β₁-blocker will be administered in an amount sufficient to providefrom about 2-900 mg per dose.

In one embodiment, compounds of the invention are administered incombination with a β₂-adrenergic receptor agonist, representativeexamples of which include, but are not limited to, albuterol,bitolterol, fenoterol, formoterol, indacaterol, isoetharine,levalbuterol, metaproterenol, pirbuterol, salbutamol, salmefamol,salmeterol, terbutaline, vilanterol, and the like Typically, theβ₂-adrenergic receptor agonist will be administered in an amountsufficient to provide from about 0.05-500 μg per dose.

In one embodiment, compounds of the invention are administered incombination with an advanced glycation end product (AGE) breaker,examples of which include, by way of illustration and not limitation,alagebrium (or ALT-711), and TRC4149.

In another embodiment, compounds of the invention are administered incombination with an aldosterone antagonist, representative examples ofwhich include, but are not limited to, eplerenone, spironolactone, andcombinations thereof. Typically, the aldosterone antagonist will beadministered in an amount sufficient to provide from about 5-300 mg perday.

In one embodiment, compounds of the invention are administered incombination with an aminopeptidase N or dipeptidyl peptidase IIIinhibitor, examples of which include, by way of illustration and notlimitation, bestatin and PC 18 (2-amino-4-methylsulfonyl butane thiol,methionine thiol).

Compounds of the invention can also be administered in combination withan angiotensin-converting enzyme (ACE) inhibitor. Representative ACEinhibitors include, but are not limited to, accupril, alacepril,benazepril, benazeprilat, captopril, ceranapril, cilazapril, delapril,enalapril, enalaprilat, fosinopril, fosinoprilat, imidapril, lisinopril,moexipril, monopril, moveltopril, pentopril, perindopril, quinapril,quinaprilat, ramipril, ramiprilat, saralasin acetate, spirapril,temocapril, trandolapril, zofenopril, and combinations thereof. In aparticular embodiment, the ACE inhibitor is selected from: benazepril,captopril, enalapril, lisinopril, ramipril, and combinations thereof.Typically, the ACE inhibitor will be administered in an amountsufficient to provide from about 1-150 mg per day.

In another embodiment, compounds of the invention are administered incombination with a dual-acting angiotensin-converting enzyme/neprilysin(ACE/NEP) inhibitor, examples of which include, but are not limited to:AVE-0848((4S,7S,12bR)-7-[3-methyl-2(S)-sulfanylbutyramido]-6-oxo-1,2,3,4,6,7,8,12b-octahydropyrido[2,1-a][2]-benzazepine-4-carboxylicacid); AVE-7688 (ilepatril) and its parent compound; BMS-182657(2-[2-oxo-3(S)-[3-phenyl-2(S)-sulfanylpropionamido]-2,3,4,5-tetrahydro-1H-1-benzazepin-1-yl]aceticacid); CGS-26303([N-[2-(biphenyl-4-yl)-1(S)-(1H-tetrazol-5-yl)ethyl]amino]methylphosphonicacid); CGS-35601(N-[1-[4-methyl-2(S)-sulfanylpentanamido]cyclopentylcarbonyl]-L-tryptophan);fasidotril; fasidotrilate; enalaprilat; ER-32935((3R,6S,9aR)-6-[3(S)-methyl-2(S)-sulfanylpentanamido]-5-oxoperhydrothiazolo[3,2-a]azepine-3-carboxylicacid); gempatrilat; MDL-101264((4S,7S,12bR)-7-[2(S)-(2-morpholinoacetylthio)-3-phenylpropionamido]-6-oxo-1,2,3,4,6,7,8,12b-octahydropyrido[2,1-a][2]benzazepine-4-carboxylicacid); MDL-101287 ([4S-[4α,7α(R*),12β]]-7-[2-(carboxymethyl)-3-phenylpropionamido]-6-oxo-1,2,3,4,6,7,8,12b-octahydropyrido[2,1-a][2]benzazepine-4-carboxylicacid); omapatrilat; RB-105(N-[2(S)-(mercaptomethyl)-3(R)-phenylbutyl]-L-alanine); sampatrilat;SA-898((2R,4R)—N-[2-(2-hydroxyphenyl)-3-(3-mercaptopropionyl)thiazolidin-4-ylcarbonyl]-L-phenylalanine);Sch-50690(N-[1(S)-carboxy-2-[N2-(methanesulfonyl)-L-lysylamino]ethyl]-L-valyl-L-tyrosine);and combinations thereof, may also be included. In one particularembodiment, the ACE/NEP inhibitor is selected from: AVE-7688,enalaprilat, fasidotril, fasidotrilate, omapatrilat, sampatrilat, andcombinations thereof.

In one embodiment, compounds of the invention are administered incombination with an angiotensin-converting enzyme 2 (ACE2) activator orstimulator.

In one embodiment, compounds of the invention are administered incombination with an angiotensin-II vaccine, examples of which include,but are not limited to ATR12181 and CYT006-AngQb.

In one embodiment, compounds of the invention are administered incombination with an anticoagulant, representative examples of whichinclude, but are not limited to: coumarins such as warfarin; heparin;and direct thrombin inhibitors such as argatroban, bivalirudin,dabigatran, and lepirudin.

In yet another embodiment, compounds of the invention are administeredin combination with an anti-diabetic agent. Representative anti-diabeticagents include injectable drugs as well as orally effective drugs, andcombinations thereof. Examples of injectable drugs include, but are notlimited to, insulin and insulin derivatives. Examples of orallyeffective drugs include, but are not limited to: biguanides such asmetformin; glucagon antagonists; α-glucosidase inhibitors such asacarbose and miglitol; dipeptidyl peptidase IV inhibitors (DPP-IVinhibitors) such as alogliptin, denagliptin, linagliptin, saxagliptin,sitagliptin, and vildagliptin; meglitinides such as repaglinide;oxadiazolidinediones; sulfonylureas such as chlorpropamide, glimepiride,glipizide, glyburide, and tolazamide; thiazolidinediones such aspioglitazone and rosiglitazone; and combinations thereof.

In another embodiment, compounds of the invention are administered incombination with antidiarrheal treatments. Representative treatmentoptions include, but are not limited to, oral rehydration solutions(ORS), loperamide, diphenoxylate, and bismuth sabsalicylate.

In yet another embodiment, a compound of the invention is administeredin combination with an anti-glaucoma agent. Representative anti-glaucomaagents include, but are not limited to: α-adrenergic agonists such asbrimonidine; β₁-adrenergic receptor antagonists; topical β₁-blockerssuch as betaxolol, levobunolol, and timolol; carbonic anhydraseinhibitors such as acetazolamide, brinzolamide, or dorzolamide;cholinergic agonists such as cevimeline and DMXB-anabaseine; epinephrinecompounds; miotics such as pilocarpine; and prostaglandin analogs.

In yet another embodiment, compounds of the invention are administeredin combination with an anti-lipid agent. Representative anti-lipidagents include, but are not limited to: cholesteryl ester transferprotein inhibitors (CETPs) such as anacetrapib, dalcetrapib, andtorcetrapib; statins such as atorvastatin, fluvastatin, lovastatin,pravastatin, rosuvastatin and simvastatin; and combinations thereof.

In one embodiment, compounds of the invention are administered incombination with an anti-thrombotic agent. Representativeanti-thrombotic agents include, but are not limited to: aspirin;anti-platelet agents such as clopidogrel, prasugrel, and ticlopidine;heparin, and combinations thereof.

In one embodiment, compounds of the invention are administered incombination with an AT₁ receptor antagonist, also known as angiotensinII type 1 receptor blockers (ARBs). Representative ARBs include, but arenot limited to, abitesartan, azilsartan (e.g., azilsartan medoxomil),benzyllosartan, candesartan, candesartan cilexetil, elisartan,embusartan, enoltasosartan, eprosartan, EXP3174, fonsartan, forasartan,glycyllosartan, irbesartan, isoteoline, losartan, medoximil,milfasartan, olmesartan (e.g., olmesartan medoxomil), opomisartan,pratosartan, ripisartan, saprisartan, saralasin, sarmesin, TAK-591,tasosartan, telmisartan, valsartan, zolasartan, and combinationsthereof. In a particular embodiment, the ARB is selected from azilsartanmedoxomil, candesartan cilexetil, eprosartan, irbesartan, losartan,olmesartan medoxomil, irbesartan, saprisartan, tasosartan, telmisartan,valsartan, and combinations thereof. Exemplary salts and/or prodrugsinclude candesartan cilexetil, eprosartan mesylate, losartan potassiumsalt, and olmesartan medoxomil. Typically, the ARB will be administeredin an amount sufficient to provide from about 4-600 mg per dose, withexemplary daily dosages ranging from 20-320 mg per day.

Compounds of the invention may also be administered in combination witha dual-acting agent, such as an AT₁ receptor antagonist/neprilysininhibitor (ARB/NEP) inhibitor, examples of which include, but are notlimited to, compounds described in U.S. Publication Nos. 2008/0269305and 2009/0023228, both to Allegretti et al. filed on Apr. 23, 2008, suchas the compound,4′-{2-ethoxy-4-ethyl-5-[((S)-2-mercapto-4-methylpentanoylamino)-methyl]imidazol-1-ylmethyl}-3′-fluorobiphenyl-2-carboxylicacid.

Compounds of the invention may also be administered in combination withmultifunctional angiotensin receptor blockers as described in Kurtz &Klein (2009) Hypertension Research 32:826-834.

In one embodiment, compounds of the invention are administered incombination with a bradykinin receptor antagonist, for example,icatibant (HOE-140). It is expected that this combination therapy maypresent the advantage of preventing angioedema or other unwantedconsequences of elevated bradykinin levels.

In one embodiment, compounds of the invention are administered incombination with a calcium channel blocker. Representative calciumchannel blockers include, but are not limited to, amlodipine, anipamil,aranipine, barnidipine, bencyclane, benidipine, bepridil, clentiazem,cilnidipine, cinnarizine, diltiazem, efonidipine, elgodipine, etafenone,felodipine, fendiline, flunarizine, gallopamil, isradipine, lacidipine,lercanidipine, lidoflazine, lomerizine, manidipine, mibefradil,nicardipine, nifedipine, niguldipine, niludipine, nilvadipine,nimodipine, nisoldipine, nitrendipine, nivaldipine, perhexiline,prenylamine, ryosidine, semotiadil, terodiline, tiapamil, verapamil, andcombinations thereof. In a particular embodiment, the calcium channelblocker is selected from amlodipine, bepridil, diltiazem, felodipine,isradipine, lacidipine, nicardipine, nifedipine, niguldipine,niludipine, nimodipine, nisoldipine, ryosidine, verapamil, andcombinations thereof. Typically, the calcium channel blocker will beadministered in an amount sufficient to provide from about 2-500 mg perdose.

In one embodiment, compounds of the invention are administered incombination with a chymase inhibitor, such as TPC-806 and2-(5-formylamino-6-oxo-2-phenyl-1,6-dihydropyrimidine-1-yl)-N-[{3,4-dioxo-1-phenyl-7-(2-pyridyloxy)}-2-heptyl]acetamide(NK3201).

In one embodiment, compounds of the invention are administered incombination with a diuretic. Representative diuretics include, but arenot limited to: carbonic anhydrase inhibitors such as acetazolamide anddichlorphenamide; loop diuretics, which include sulfonamide derivativessuch as acetazolamide, ambuside, azosernide, bumetanide, butazolamide,chloraminophenamide, clofenamide, clopamide, clorexolone, disulfamide,ethoxolamide, furosemide, mefruside, methazolamide, piretanide,torsemide, tripamide, and xipamide, as well as non-sulfonamide diureticssuch as ethacrynic acid and other phenoxyacetic acid compounds such astienilic acid, indacrinone and quincarbate; osmotic diuretics such asmannitol; potassium-sparing diuretics, which include aldosteroneantagonists such as spironolactone, and Na⁺ channel inhibitors such asamiloride and triamterene; thiazide and thiazide-like diuretics such asalthiazide, bendroflumethiazide, benzylhydrochlorothiazide,benzthiazide, buthiazide, chlorthalidone, chlorothiazide,cyclopenthiazide, cyclothiazide, epithiazide, ethiazide, fenquizone,flumethiazide, hydrochlorothiazide, hydroflumethiazide, indapamide,methylclothiazide, meticrane, metolazone, paraflutizide, polythiazide,quinethazone, teclothiazide, and trichloromethiazide; and combinationsthereof. In a particular embodiment, the diuretic is selected fromamiloride, bumetanide, chlorothiazide, chlorthalidone, dichlorphenamide,ethacrynic acid, furosemide, hydrochlorothiazide, hydroflumethiazide,indapamide, methylclothiazide, metolazone, torsemide, triamterene, andcombinations thereof. The diuretic will be administered in an amountsufficient to provide from about 5-50 mg per day, more typically 6-25 mgper day, with common dosages being 6.25 mg, 12.5 mg or 25 mg per day.

Compounds of the invention may also be administered in combination withan endothelin converting enzyme (ECE) inhibitor, examples of whichinclude, but are not limited to, phosphoramidon, CGS 26303, andcombinations thereof.

In a particular embodiment, compounds of the invention are administeredin combination with an endothelin receptor antagonist. Representativeendothelin receptor antagonists include, but are not limited to:selective endothelin receptor antagonists that affect endothelin Areceptors, such as avosentan, ambrisentan, atrasentan, BQ-123,clazosentan, darusentan, sitaxentan, and zibotentan; and dual endothelinreceptor antagonists that affect both endothelin A and B receptors, suchas bosentan, macitentan, tezosentan).

In yet another embodiment, a compound of the invention is administeredin combination with one or more HMG-CoA reductase inhibitors, which arealso known as statins. Representative statins include, but are notlimited to, atorvastatin, fluvastatin, lovastatin, pitavastatin,pravastatin, rosuvastatin and simvastatin.

In one embodiment, compounds of the invention are administered incombination with a monoamine reuptake inhibitor, examples of whichinclude, by way of illustration and not limitation, norepinephrinereuptake inhibitors such as atomoxetine, buproprion and the buproprionmetabolite hydroxybuproprion, maprotiline, reboxetine, and viloxazine;selective serotonin reuptake inhibitors (SSRIs) such as citalopram andthe citalopram metabolite desmethylcitalopram, dapoxetine, escitalopram(e.g., escitalopram oxalate), fluoxetine and the fluoxetine desmethylmetabolite norfluoxetine, fluvoxamine (e.g., fluvoxamine maleate),paroxetine, sertraline and the sertraline metabolite demethylsertraline;dual serotonin-norepinephrine reuptake inhibitors (SNRIs) such asbicifadine, duloxetine, milnacipran, nefazodone, and venlafaxine; andcombinations thereof.

In another embodiment, compounds of the invention are administered incombination with a muscle relaxant, examples of which include, but arenot limited to: carisoprodol, chlorzoxazone, cyclobenzaprine,diflunisal, metaxalone, methocarbamol, and combinations thereof.

In one embodiment, compounds of the invention are administered incombination with a natriuretic peptide or analog, examples of whichinclude but are not limited to: carperitide, CD-NP (Nile Therapeutics),CU-NP, nesiritide, PL-3994 (Palatin Technologies, Inc.), ularitide,cenderitide, and compounds described in Ogawa et al (2004) J. Biol.Chem. 279:28625-31. These compounds are also referred to as natriureticpeptide receptor-A (NPR-A) agonists. In another embodiment, compounds ofthe invention are administered in combination with a natriuretic peptideclearance receptor (NPR-C) antagonist such as SC-46542, cANF (4-23), andAP-811 (Veale (2000) Bioorg Med Chem Lett 10:1949-52). For example,AP-811 has shown synergy when combined with the NEP inhibitor, thiorphan(Wegner (1995) Clin. Exper. Hypert. 17:861-876).

In another embodiment, compounds of the invention are administered incombination with a neprilysin (NEP) inhibitor. Representative NEPinhibitors include, but are not limited to: AHU-377; candoxatril;candoxatrilat; dexecadotril((+)-N-[2(R)-(acetylthiomethyl)-3-phenylpropionyl]glycine benzyl ester);CGS-24128(3-[3-(biphenyl-4-yl)-2-(phosphonomethylamino)propionamido]propionicacid); CGS-24592((S)-3-[3-(biphenyl-4-yl)-2-(phosphonomethylamino)propionamido]propionicacid); CGS-25155(N-[9(R)-(acetylthiomethyl)-10-oxo-1-azacyclodecan-2(S)-ylcarbonyl]-4(R)-hydroxy-L-prolinebenzyl ester); 3-(1-carbamoylcyclohexyl)propionic acid derivativesdescribed in WO 2006/027680 to Hepworth et al. (Pfizer Inc.); JMV-390-1(2(R)-benzyl-3-(N-hydroxycarbamoyl)propionyl-L-isoleucyl-L-leucine);ecadotril; phosphoramidon; retrothiorphan; RU-42827(2-(mercaptomethyl)-N-(4-pyridinyl)benzenepropionamide); RU-44004(N-(4-morpholinyl)-3-phenyl-2-(sulfanylmethyl)propionamide); SCH-32615((S)—N—[N-(1-carboxy-2-phenylethyl)-L-phenylalanyl]-β-alanine) and itsprodrug SCH-34826((S)—N—[N-[1-[[(2,2-dimethyl-1,3-dioxolan-4-yl)methoxy]carbonyl]-2-phenylethyl]-L-phenylalanyl]-β-alanine);sialorphin; SCH-42495(N-[2(S)-(acetylsulfanylmethyl)-3-(2-methylphenyl)propionyl]-L-methionineethyl ester); spinorphin; SQ-28132(N-[2-(mercaptomethyl)-1-oxo-3-phenylpropyl]leucine); SQ-28603(N-[2-(mercaptomethyl)-1-oxo-3-phenylpropyl]-β-alanine); SQ-29072(7-[[2-(mercaptomethyl)-1-oxo-3-phenylpropyl]amino]heptanoic acid);thiorphan and its prodrug racecadotril; UK-69578(cis-4-[[[1-[2-carboxy-3-(2-methoxyethoxy)propyl]cyclopentyl]carbonyl]amino]cyclohexanecarboxylicacid); UK-447,841(2-{1-[3-(4-chlorophenyl)propylcarbamoyl]-cyclopentylmethyl}-4-methoxybutyricacid); UK-505,749((R)-2-methyl-3-{1-[3-(2-methylbenzothiazol-6-yl)propylcarbamoyl]cyclopentyl}propionicacid); 5-biphenyl-4-yl-4-(3-carboxypropionylamino)-2-methylpentanoicacid and 5-biphenyl-4-yl-4-(3-carboxypropionylamino)-2-methylpentanoicacid ethyl ester (WO 2007/056546); daglutril[(3S,2′R)-3-{1-[2′-(ethoxycarbonyl)-4′-phenylbutyl]-cyclopentan-1-carbonylamino}-2,3,4,5-tetrahydro-2-oxo-1H-1-benzazepine-1-aceticacid] described in WO 2007/106708 to Khder et al. (Novartis AG); andcombinations thereof. In a particular embodiment, the NEP inhibitor isselected from AHU-377, candoxatril, candoxatrilat, CGS-24128,phosphoramidon, SCH-32615, SCH-34826, SQ-28603, thiorphan, andcombinations thereof. In a particular embodiment, the NEP inhibitor is acompound such as daglutril, which also has activity both as an inhibitorof the endothelin converting enzyme (ECE) and of NEP. Other dual actingECE/NEP compounds can also be used. The NEP inhibitor will beadministered in an amount sufficient to provide from about 20-800 mg perday, with typical daily dosages ranging from 50-700 mg per day, morecommonly 100-600 or 100-300 mg per day.

In one embodiment, compounds of the invention are administered incombination with a nitric oxide donor, examples of which include, butare not limited to nicorandil; organic nitrates such as pentaerythritoltetranitrate; and sydnonimines such as linsidomine and molsidomine.

In yet another embodiment, compounds of the invention are administeredin combination with a non-steroidal anti-inflammatory agent (NSAID).Representative NSAIDs include, but are not limited to: acemetacin,acetyl salicylic acid, alclofenac, alminoprofen, amfenac, amiprilose,amoxiprin, anirolac, apazone, azapropazone, benorilate, benoxaprofen,bezpiperylon, broperamole, bucloxic acid, carprofen, clidanac,diclofenac, diflunisal, diftalone, enolicam, etodolac, etoricoxib,fenbufen, fenclofenac, fenclozic acid, fenoprofen, fentiazac, feprazone,flufenamic acid, flufenisal, fluprofen, flurbiprofen, furofenac,ibufenac, ibuprofen, indomethacin, indoprofen, isoxepac, isoxicam,ketoprofen, ketorolac, lofemizole, lornoxicam, meclofenamate,meclofenamic acid, mefenamic acid, meloxicam, mesalamine, miroprofen,mofebutazone, nabumetone, naproxen, niflumic acid, oxaprozin, oxpinac,oxyphenbutazone, phenylbutazone, piroxicam, pirprofen, pranoprofen,salsalate, sudoxicam, sulfasalazine, sulindac, suprofen, tenoxicam,tiopinac, tiaprofenic acid, tioxaprofen, tolfenamic acid, tolmetin,triflumidate, zidometacin, zomepirac, and combinations thereof. In aparticular embodiment, the NSAID is selected from etodolac,flurbiprofen, ibuprofen, indomethacin, ketoprofen, ketorolac, meloxicam,naproxen, oxaprozin, piroxicam, and combinations thereof.

In one embodiment, compounds of the invention are administered incombination with an N-methyl d-aspartate (NMDA) receptor antagonist,examples of which include, by way of illustration and not limitation,including amantadine, dextromethorphan, dextropropoxyphene, ketamine,ketobemidone, memantine, methadone, and so forth.

In still another embodiment, compounds of the invention are administeredin combination with an opioid receptor agonist (also referred to asopioid analgesics). Representative opioid receptor agonists include, butare not limited to: buprenorphine, butorphanol, codeine, dihydrocodeine,fentanyl, hydrocodone, hydromorphone, levallorphan, levorphanol,meperidine, methadone, morphine, nalbuphine, nalmefene, nalorphine,naloxone, naltrexone, nalorphine, oxycodone, oxymorphone, pentazocine,propoxyphene, tramadol, and combinations thereof. In certainembodiments, the opioid receptor agonist is selected from codeine,dihydrocodeine, hydrocodone, hydromorphone, morphine, oxycodone,oxymorphone, tramadol, and combinations thereof.

In a particular embodiment, compounds of the invention are administeredin combination with a phosphodiesterase (PDE) inhibitor, particularly aPDE-V inhibitor. Representative PDE-V inhibitors include, but are notlimited to, avanafil, lodenafil, mirodenafil, sildenafil (Revatio®),tadalafil (Adcirca®), vardenafil (Levitra®), and udenafil.

In another embodiment, compounds of the invention are administered incombination with a prostaglandin analog (also referred to as prostanoidsor prostacyclin analogs). Representative prostaglandin analogs include,but are not limited to, beraprost sodium, bimatoprost, epoprostenol,iloprost, latanoprost, tafluprost, travoprost, and treprostinil, withbimatoprost, latanoprost, and tafluprost being of particular interest.

In yet another embodiment, compounds of the invention are administeredin combination with a prostaglandin receptor agonist, examples of whichinclude, but are not limited to, bimatoprost, latanoprost, travoprost,and so forth.

Compounds of the invention may also be administered in combination witha renin inhibitor, examples of which include, but are not limited to,aliskiren, enalkiren, remikiren, and combinations thereof.

In another embodiment, compounds of the invention are administered incombination with a selective serotonin reuptake inhibitor (SSRI).Representative SSRIs include, but are not limited to: citalopram and thecitalopram metabolite desmethylcitalopram, dapoxetine, escitalopram(e.g., escitalopram oxalate), fluoxetine and the fluoxetine desmethylmetabolite norfluoxetine, fluvoxamine (e.g., fluvoxamine maleate),paroxetine, sertraline and the sertraline metabolite demethylsertraline,and combinations thereof.

In one embodiment, compounds of the invention are administered incombination with a 5-HT_(1D) serotonin receptor agonist, examples ofwhich include, by way of illustration and not limitation, triptans suchas almotriptan, avitriptan, eletriptan, frovatriptan, naratriptanrizatriptan, sumatriptan, and zolmitriptan.

In one embodiment, compounds of the invention are administered incombination with a sodium channel blocker, examples of which include, byway of illustration and not limitation, carbamazepine, fosphenytoin,lamotrignine, lidocaine, mexiletine, oxcarbazepine, phenytoin, andcombinations thereof.

In one embodiment, compounds of the invention are administered incombination with a soluble guanylate cyclase stimulator or activator,examples of which include, but are not limited to ataciguat, riociguat,and combinations thereof.

In one embodiment, compounds of the invention are administered incombination with a tricyclic antidepressant (TCA), examples of whichinclude, by way of illustration and not limitation, amitriptyline,amitriptylinoxide, butriptyline, clomipramine, demexiptiline,desipramine, dibenzepin, dimetacrine, dosulepin, doxepin, imipramine,imipraminoxide, lofepramine, melitracen, metapramine, nitroxazepine,nortriptyline, noxiptiline, pipofezine, propizepine, protriptyline,quinupramine, and combinations thereof.

In one embodiment, compounds of the invention are administered incombination with a vasopressin receptor antagonist, examples of whichinclude, by way of illustration and not limitation, conivaptan andtolvaptan.

Combined secondary therapeutic agents may also be helpful in furthercombination therapy with compounds of the invention. For example,compounds of the invention can be combined with a diuretic and an ARB,or a calcium channel blocker and an ARB, or a diuretic and an ACEinhibitor, or a calcium channel blocker and a statin. Specific examplesinclude, a combination of the ACE inhibitor enalapril (in the maleatesalt form) and the diuretic hydrochlorothiazide, which is sold under themark Vaseretic®, or a combination of the calcium channel blockeramlodipine (in the besylate salt form) and the ARB olmesartan (in themedoxomil prodrug form), or a combination of a calcium channel blockerand a statin, all may also be used with the compounds of the invention.Other therapeutic agents such as α₂-adrenergic receptor agonists andvasopressin receptor antagonists may also be helpful in combinationtherapy. Exemplary α₂-adrenergic receptor agonists include clonidine,dexmedetomidine, and guanfacine.

The following formulations illustrate representative pharmaceuticalcompositions of the invention.

Exemplary Hard Gelatin Capsules for Oral Administration

A compound of the invention (50 g), 440 g spray-dried lactose and 10 gmagnesium stearate are thoroughly blended. The resulting composition isthen loaded into hard gelatin capsules (500 mg of composition percapsule). Alternately, a compound of the invention (20 mg) is thoroughlyblended with starch (89 mg), microcrystalline cellulose (89 mg) andmagnesium stearate (2 mg). The mixture is then passed through a No. 45mesh U.S. sieve and loaded into a hard gelatin capsule (200 mg ofcomposition per capsule).

Alternately, a compound of the invention (30 g), a secondary agent (20g), 440 g spray-dried lactose and 10 g magnesium stearate are thoroughlyblended, and processed as described above.

Exemplary Gelatin Capsule Formulation for Oral Administration

A compound of the invention (100 mg) is thoroughly blended withpolyoxyethylene sorbitan monooleate (50 mg) and starch powder (250 mg).The mixture is then loaded into a gelatin capsule (400 mg of compositionper capsule). Alternately, a compound of the invention (70 mg) and asecondary agent (30 mg) are thoroughly blended with polyoxyethylenesorbitan monooleate (50 mg) and starch powder (250 mg), and theresulting mixture loaded into a gelatin capsule (400 mg of compositionper capsule).

Alternately, a compound of the invention (40 mg) is thoroughly blendedwith microcrystalline cellulose (Avicel PH 103; 259.2 mg) and magnesiumstearate (0.8 mg). The mixture is then loaded into a gelatin capsule(Size #1, White, Opaque) (300 mg of composition per capsule).

Exemplary Tablet Formulation for Oral Administration

A compound of the invention (10 mg), starch (45 mg) and microcrystallinecellulose (35 mg) are passed through a No. 20 mesh U.S. sieve and mixedthoroughly. The granules so produced are dried at 50-60° C. and passedthrough a No. 16 mesh U.S. sieve. A solution of polyvinylpyrrolidone (4mg as a 10% solution in sterile water) is mixed with sodiumcarboxymethyl starch (4.5 mg), magnesium stearate (0.5 mg), and talc (1mg), and this mixture is then passed through a No. 16 mesh U.S. sieve.The sodium carboxymethyl starch, magnesium stearate and talc are thenadded to the granules. After mixing, the mixture is compressed on atablet machine to afford a tablet weighing 100 mg.

Alternately, a compound of the invention (250 mg) is thoroughly blendedwith microcrystalline cellulose (400 mg), silicon dioxide fumed (10 mg),and stearic acid (5 mg). The mixture is then compressed to form tablets(665 mg of composition per tablet).

Alternately, a compound of the invention (400 mg) is thoroughly blendedwith cornstarch (50 mg), croscarmellose sodium (25 mg), lactose (120mg), and magnesium stearate (5 mg). The mixture is then compressed toform a single-scored tablet (600 mg of composition per tablet).

Alternately, a compound of the invention (100 mg) is thoroughly blendedwith cornstarch (100 mg) with an aqueous solution of gelatin (20 mg).The mixture is dried and ground to a fine powder. Microcrystallinecellulose (50 mg) and magnesium stearate (5 mg) are then admixed withthe gelatin formulation, granulated and the resulting mixture compressedto form tablets (100 mg of the compound of the invention per tablet).

Exemplary Suspension Formulation for Oral Administration

The following ingredients are mixed to form a suspension containing 100mg of the compound of the invention per 10 mL of suspension:

Ingredients Amount Compound of the invention 1.0 g Fumaric acid 0.5 gSodium chloride 2.0 g Methyl paraben 0.15 g Propyl paraben 0.05 gGranulated sugar 25.5 g Sorbitol (70% solution) 12.85 g Veegum ® K(magnesium aluminum silicate) 1.0 g Flavoring 0.035 mL Colorings 0.5 mgDistilled water q.s. to 100 mL

Exemplary Liquid Formulation for Oral Administration

A suitable liquid formulation is one with a carboxylic acid-based buffersuch as citrate, lactate and maleate buffer solutions. For example, acompound of the invention (which may be pre-mixed with DMSO) is blendedwith a 100 mM ammonium citrate buffer and the pH adjusted to pH 5, or isblended with a 100 mM citric acid solution and the pH adjusted to pH 2.Such solutions may also include a solubilizing excipient such as acyclodextrin, for example the solution may include 10 wt %hydroxypropyl-3-cyclodextrin.

Other suitable formulations include a 5% NaHCO₃ solution, with orwithout cyclodextrin.

Exemplary Injectable Formulation for Administration by Injection

A compound of the invention (0.2 g) is blended with 0.4 M sodium acetatebuffer solution (2.0 mL). The pH of the resulting solution is adjustedto pH 4 using 0.5 N aqueous hydrochloric acid or 0.5 N aqueous sodiumhydroxide, as necessary, and then sufficient water for injection isadded to provide a total volume of 20 mL. The mixture is then filteredthrough a sterile filter (0.22 micron) to provide a sterile solutionsuitable for administration by injection.

Exemplary Compositions for Administration by Inhalation

A compound of the invention (0.2 mg) is micronized and then blended withlactose (25 mg). This blended mixture is then loaded into a gelatininhalation cartridge. The contents of the cartridge are administeredusing a dry powder inhaler, for example.

Alternately, a micronized compound of the invention (10 g) is dispersedin a solution prepared by dissolving lecithin (0.2 g) in demineralizedwater (200 mL). The resulting suspension is spray dried and thenmicronized to form a micronized composition comprising particles havinga mean diameter less than about 1.5 m. The micronized composition isthen loaded into metered-dose inhaler cartridges containing pressurized1,1,1,2-tetrafluoroethane in an amount sufficient to provide about 10 μgto about 500 μg of the compound of the invention per dose whenadministered by the inhaler.

Alternately, a compound of the invention (25 mg) is dissolved in citratebuffered (pH 5) isotonic saline (125 mL). The mixture is stirred andsonicated until the compound is dissolved. The pH of the solution ischecked and adjusted, if necessary, to pH 5 by slowly adding aqueous 1 NNaOH. The solution is administered using a nebulizer device thatprovides about 10 μg to about 500 μg of the compound of the inventionper dose.

EXAMPLES

The following Preparations and Examples are provided to illustratespecific embodiments of the invention. These specific embodiments,however, are not intended to limit the scope of the invention in any wayunless specifically indicated.

The following abbreviations have the following meanings unless otherwiseindicated and any other abbreviations used herein and not defined havetheir standard, generally accepted meaning:

-   -   AcOH acetic acid    -   (Boc)₂O di-t-butyl dicarbonate    -   DCC dicyclohexylcarbodiimide    -   DCM dichloromethane or methylene chloride    -   DIBAL diisobutylaluminum hydride    -   DIPEA N,N-diisopropylethylamine    -   DMAP 4-dimethylaminopyridine    -   DMF N,N-dimethylformamide    -   DMSO dimethyl sulfoxide    -   Dnp 2,4-dinitrophenyl    -   EDCI N-(3-dimethylaminopropyl)-N′-ethylcarbodiimide    -   Et₃N triethylamine    -   Et₂O diethyl ether    -   EtOAc ethyl acetate    -   EtOH ethanol    -   HATU N,N,N′,N′-tetramethyl-O-(7-azabenzotriazol-1-yl)uronium        hexafluorophosphate    -   HCTU        (2-(6-chloro-1H-benzotriazole-1-yl)-1,1,3,3-tetramethylaminium        hexafluorophosphate)    -   HEPES 4-(2-hydroxyethyl)-1-piperazineethanesulfonic acid    -   HOAt 1-hydroxy-7-azabenzotriazole    -   LiHMDS lithium hexamethyl disilazide    -   Mca (7-methoxycoumarin-4-yl)acyl    -   MeCN acetonitrile    -   MeOH methanol    -   Pd(PPh₃)₄ tetrakis(triphenylphosphine)palladium(0)    -   SilicaCat®DPP-Pd silica based diphenylphosphine palladium (II)        catalyst    -   SilicaCat®Pd(0) silica based palladium (0) catalyst    -   TFA trifluoroacetic acid    -   THF tetrahydrofuran

Unless noted otherwise, all materials, such as reagents, startingmaterials and solvents, were purchased from commercial suppliers (suchas Sigma-Aldrich, Fluka Riedel-de Haën, and the like) and were usedwithout further purification.

Reactions were run under nitrogen atmosphere, unless noted otherwise.The progress of reactions were monitored by thin layer chromatography(TLC), analytical high performance liquid chromatography (anal. HPLC),and mass spectrometry, the details of which are given in specificexamples. Solvents used in analytical HPLC were as follows: solvent Awas 98% H₂O/2% MeCN/1.0 mL/L TFA; solvent B was 90% MeCN/10% H₂O/1.0mL/L TFA.

Reactions were worked up as described specifically in each preparationfor example; commonly reaction mixtures were purified by extraction andother purification methods such as temperature-, and solvent-dependentcrystallization, and precipitation. In addition, reaction mixtures wereroutinely purified by preparative HPLC, typically using Microsorb C18and Microsorb BDS column packings and conventional eluents. Progress ofreactions was typically measured by liquid chromatography massspectrometry (LCMS). Characterization of isomers were done by NuclearOverhauser effect spectroscopy (NOE). Characterization of reactionproducts was routinely carried out by mass and ¹H-NMR spectrometry. ForNMR measurement, samples were dissolved in deuterated solvent (CD₃OD,CDCl₃, or DMSO-d₆), and ¹H-NMR spectra were acquired with a VarianGemini 2000 instrument (400 MHz) under standard observation conditions.Mass spectrometric identification of compounds was typically conductedusing an electrospray ionization method (ESMS) with an AppliedBiosystems (Foster City, Calif.) model API 150 EX instrument or anAgilent (Palo Alto, Calif.) model 1200 LC/MSD instrument.

Preparation 1Oxodiperoxymolybdenum(pyridine)(hexamethylphosphorictriamide)

MoO₃→MoO₅.H₂O(Me₂N)₃PO→MoO₅.(Me₂N)₃PO→MoO₅.Py.(Me₂N)₃PO

Molybdenum oxide (MoO₃; 30 g, 0.2 mol) and 30% hydrogen peroxide (150mL) were combined, with stirring. The reaction vessel was placed in anoil bath equilibrated at 40° C. and heated until the internaltemperature reached 35° C. The heating bath was then removed andreplaced by a water bath to control the mildly exothermic reaction sothat an internal temperature of 35-40° C. was maintained. After theinitial exothermic period (˜30 minutes), the reaction vessel wasreturned to the 40° C. oil bath and stirred for a total of 3.5 hours toform a yellow solution with a small amount of suspended white solid.After cooling to 20° C., the solution was filtered and the resultingyellow filtrate was cooled to 10° C. (ice bath with stirring) andhexamethylphosphoric triamide ((Me₂N)₃PO; HMPA; 37.3 g, 0.2 mol) wasadded dropwise over 5 minutes, resulting in the formation of a yellowcrystalline precipitate. Stirring was continued for a total of 15minutes at 10° C., and the product was filtered and pressed dry. After30 minutes under vacuum, the filter cake was combined with MeOH (20 mL)and stirred at 40° C. Additional MeOH was slowly added until the solidsdissolved. The saturated solution was cooled in the refrigerator,yielding a yellow solid (appeared as needles). The solid mass wasphysically broken, filtered and washed with cold MeOH (20-30 mL) toyield oxodiperoxymolybdenum(aqua) (hexamethylphosphoric triamide)(MoO₅.H₂O.HMPA, 46-50 g).

MoO₅.H₂O.HMPA was dried over phosphorus oxide in a vacuum desiccator,shielded from the light, for 24 hours at 0.2 mm Hg to yield a somewhathygroscopic yellow solid, MoO₅.HMPA. MoO5.HMPA (36.0 g, 0.1 mol) wasdissolved in THF (150 mL) and the solution was filtered to remove anyprecipitate. The filtrate was then stirred at 20° C. while dry pyridine(8.0 g, 0.1 mol) was added over 10 minutes. The crystalline, yellowproduct was collected, washed with dry THF (25 mL) and anhydrous ether(200 mL) and dried in a vacuum desiccator (1 hour, 0.2 mm Hg) to yieldthe title compound, oxodiperoxymolybdenum(pyridine)(hexamethylphosphorictriamide) (MoO₅.Py.HMPA) as a finely divided yellow solid (36-38 g).

Preparation 2 (S)-2-Biphenyl-4-ylmethyl-5-oxopyrrolidine-1-carboxylicAcid t-Butyl Ester

To a stirred solution of(R)-3-biphenyl-4-yl-2-t-butoxycarbonylaminopropionic acid (50 g, 146.5mmol), Meldrum's acid (23.3 g, 161.1 mmol) and DMAP (27.8 g, 227 mmol)in anhydrous DCM (500 mL) was added a solution of DCC (33.3 g, 161.1mmol) in anhydrous DCM (200 mL) over 1 hour at −5° C. under nitrogen.The mixture was stirred at −5° C. for 8 hours, then refrigeratedovernight, during which tiny crystals of dicyclohexylurea precipitated.After filtration the mixture was washed with 5% KHSO₄ (4×200 mL),saturated aqueous NaCl (1×200 mL) and dried over MgSO₄ overnight. Theresulting solution was evaporated to give the crude compound 1 (68 g) asa light yellow solid). LC-MS: [M⁺Na]: 490, [2M⁺Na]: 957.

To a solution of crude compound 1 (68 g, 146.5 mmol) in anhydrous DCM(1000 mL) was added AcOH (96.8 g, 1.6 mol) at −5° C. under nitrogen. Theresulting mixture was stirred at −5° C. for 0.5 hours, then NaBH₄ (13.9g, 366 mmol) was added in small portions over 2 hours. After stirringfor another hour at −5° C., saturated aqueous NaCl (300 mL) was added.The organic layer was washed with saturated aqueous NaCl (2×300 mL) thenwater (2×300 mL), dried over MgSO₄, filtered, and evaporated to give thecrude compound 2, which was further purified by chromatography(hexanes:EtOAc=5:1) to give purified compound 2 (46 g) as a light yellowsolid. LC-MS: [M⁺Na]: 476, [2M Na]: 929.

A stirred solution of purified compound 2 (46 g, 101 mmol) in anhydroustoluene (300 mL) was heated to reflux under nitrogen for 3 hours. Afterevaporation of the solvent, the residue was purified by chromatography(hexanes:EtOAc=10:1) to yield the title compound (27 g) as a lightyellow solid.

LC-MS: [M⁺Na]: 374, [2M Na]: 725; 1H NMR (300 MHz, CDCl₃): δ7.64-7.62(m, 4H), 7.51-7.46 (m, 2H), 7.42-7.39 (m, 1H), 7.39-7.30 (m, 2H),4.50-4.43 (m, 1H), 3.27-3.89 (m, 1H), 2.88-2.80 (m, 1H), 2.48-2.42 (m,2H), 2.09-1.88 (m, 2H), 1.66 (s, 9H).

Preparation 3 (2R,4R)-4-Amino-5-biphenyl-4-yl-2-hydroxypentanoic AcidEthyl Ester and (2R,4S)-4-Amino-5-biphenyl-4-yl-2-hydroxypentanoic AcidEthyl Ester

Step 1: To a stirred solution of(S)-2-biphenyl-4-ylmethyl-5-oxopyrrolidine-1-carboxylic acid t-butylester (4.4 g, 12.4 mmol) in anhydrous THF (70 mL) was added a solutionof 1 M LiHMDS in THF (28 mL) over 15 minutes at −65° C. under nitrogen.After stirring for 3 hours at −65° C.,oxodiperoxymolybdenum(pyridine)(hexamethylphosphorictriamide) (9 g, 18.6mmol) was added. The mixture was stirred for another 2 hours at −35° C.,then saturated aqueous Na₂S₂O₃ (60 mL) was added. The organic layer wascollected and washed with saturated aqueous NH₄Cl (60 mL×3) andsaturated aqueous NaCl (60 mL×2), then dried over Na₂SO₄, and thesolvent was removed under reduced pressure to yield the crude productwhich was further purified by chromatography (hexanes:EtOAc=5:1) toyield compound 1 as a white solid (1.8 g). LC-MS: [2M⁺Na]: 757.

Step 2: To a solution of compound 1 (1.8 g, 5.0 mmol) in anhydrous DCM(50 mL) was added DMAP (122 mg, 1 mmol) and Et₃N (1.5 g, 14.9 mmol) at0° C. under nitrogen. After stirring for 0.5 hour at 0° C., benzylchloride (1.0 g, 7.4 mmol) was added over 15 minutes. The mixture wasstirred for an additional 2 hours at 0° C., then saturated aqueousNaHCO₃ (50 mL) was added. The organic layer was collected and washedwith saturated aqueous NaHCO₃ (50 mL×2) and saturated aqueous NaCl (50mL×1), then dried over Na₂SO₄. The solids were filtered out and thefiltrate was concentrated to yield the crude product which was furtherpurified by chromatography (hexanes:EtOAc=4:1) to yield compound 2A (471mg) and compound 2B (883 mg) as white solids. LC-MS: [M⁺Na]: 494;[2M⁺Na]: 965.

Compound 2A: ¹H NMR (300 MHz, CDCl₃): δ (ppm)=8.02 (m, 2H), 7.57-7.25(m, 12H), 5.42 (m, 1H), 4.50 (m, 1H), 3.26-3.21 (m, 1H), 2.90 (m, 1H),2.58 (m, 1H), 2.15-2.05 (m, 1H), 1.62 (m, 9H)

Compound 2B: ¹H NMR (300 MHz, CDCl₃): δ (ppm)=8.06 (m, 2H), 7.58-7.18(m, 12H), 5.53-5.41 (m, 1H), 4.39 (m, 1H), 3.57-3.54 (m, 1H), 2.87-2.80(m, 1H), 2.48-2.44 (m, 1H), 1.98 (m, 1H), 1.63 (m, 9H).

Step 3: To a stirred solution of compound 2A (471 mg, 1 mmol) inanhydrous EtOH (10 mL) was added anhydrous K₂CO₃ (691 mg, 5 mmol) atroom temperature under nitrogen. After stirring for 20 hours at roomtemperature, the solids were filtered out. To the filtrate was addedwater (30 mL), DCM (30 mL) and saturated aqueous NaCl (5 mL). Theaqueous layer was separated and extracted with DCM (30 mL×3). Thecombined organic layers were washed with saturated aqueous NaCl (50 mL),dried over Na₂SO₄, and concentrated to yield the crude product which wasfurther purified by chromatography (hexanes:EtOAc=6:1) to yield compound3 as a white solid (275 mg). LC-MS: [M+Na]: 436, [2M+Na]: 849.

Step 4: To EtOH (5 mL) was added acetyl chloride (685 mg) at −30° C.After stirring for 1 hour at −30° C., a solution of compound 3 (275 mg,665 μmol) in anhydrous EtOH (5 mL) was added. The mixture was heated to25° C. and stirred for 3 hours at 25° C. After evaporation of thesolvent, the residue was washed with cold anhydrous Et₂O (10 mL) toyield (2R,4R)-4-amino-5-biphenyl-4-yl-2-hydroxypentanoic acid ethylester as a white solid HCl salt (207 mg). LC-MS: [M+H]: 314, [2M⁺Na]:649.

¹H NMR (300 MHz, CDCl₃): δ (ppm)=7.99 (m, 3H), 7.66-7.64 (m, 4H),7.48-7.35 (m, 5H), 6.08 (m, 1H), 4.21 (m, 1H), 4.09-4.05 (m, 2H), 3.52(m, 1H), 2.97-2.95 (m, 2H), 1.89-1.87 (m, 2H), 1.19-1.14 (m, 3H).

Step 5: To a stirred solution of compound 2B (883 mg, 1.9 mmol) inanhydrous EtOH (15 mL) was added anhydrous K₂CO₃ (1293 mg, 9.4 mmol) atroom temperature under nitrogen. After stirring for 20 hours at roomtemperature, the solids were filtered out. To the filtrate was addedwater (30 mL), DCM (30 mL) and saturated aqueous NaCl (5 mL). Theaqueous layer was separated and extracted with DCM (30 mL×3). Thecombined organic layers were washed with saturated aqueous NaCl (50 mL),dried over Na₂SO₄, and concentrated to yield the crude product which wasfurther purified by chromatography (hexanes:EtOAc=6:1) to yield compound4 as a white solid (524 mg). LC-MS: [M+Na]: 436, [2M+Na]: 849.

Step 6: To EtOH (8 mL) was added acetyl chloride (1300 mg) at −30° C.After stirring for 1 hour at −30° C., a solution of compound 4 (524 mg,1.3 mmol) in anhydrous EtOH (8 mL) was added. The mixture was heated to25° C. and stirred for 3 hours at 25° C. After evaporation of thesolvent, the residue was washed with cold anhydrous Et₂O (10 mL) toyield (2R,4S)-4-amino-5-biphenyl-4-yl-2-hydroxypentanoic acid ethylester as a white solid HCl salt (395 mg). LC-MS: [M+H]: 314, [2M+Na]:649.

¹H NMR (300 MHz, CDCl₃): δ (ppm)=8.14 (m, 3H), 7.66-7.62 (m, 4H),7.47-7.31 (m, 5H), 5.87-5.85 (m, 1H), 4.34 (m, 1H), 4.08-4.00 (m, 2H),3.48 (m, 1H), 3.09 (m, 1H), 2.85-2.81 (m, 1H), 1.88 (m, 1H), 1.76 (m,1H), 1.15-1.10 (m, 3H).

Alternate Synthesis of(2R,4R)-4-Amino-5-biphenyl-4-yl-2-hydroxypentanoic Acid Ethyl Ester

A solution of[(S)-2-Biphenyl-4-yl-1-(2,2-dimethyl-4,6-dioxo-[1,3]dioxan-5-ylmethyl)ethyl]-carbamicacid t-butyl ester (143 g, 320 mmol) in anhydrous toluene (1 L) washeated to reflux under nitrogen overnight. The solvent was removed underreduced pressure to give(S)-2-biphenyl-4-ylmethyl-5-oxopyrrolidine-1-carboxylic acid t-butylester, which was directly used without further purification and added toa solution of 3N HCl in EtOAc (1.2 L). The resulting mixture was stirredfor 3 hours at room temperature. The solvent was removed in vacuo. Theresidue was re-crystallized in EtOAc (300 mL) to yield a first batch ofthe deprotected compound (56 g). The mother liquid was subject tochromatography column (eluted by EtOAc and hexanes from 1:1 to 100%EtOAc) to yield a second batch of the deprotected compound (8 g). To asuspension of the deprotected compound (64 g, 250 mmol) in anhydrous THF(500 mL) was added dropwise BuLi (100 mL, 2.5 M in hexanes) at −78° C.After stirring for 0.5 hour, pivaloyl chloride (34 g, 0.28 mol) wasadded dropwise. The mixture was stirred for 1 hour at −78° C. Thereaction was then quenched with saturated aqueous NH₄Cl, and the mixtureextracted with EtOAc. The extract was dried over MgSO₄ and concentratedto yield(S)-5-biphenyl-4-ylmethyl-1-(2,2-dimethylpropionyl)pyrrolidin-2-one (85g) as white solid.

(S)-5-Biphenyl-4-ylmethyl-1-(2,2-dimethylpropionyl)pyrrolidin-2-one (40g, 120 mmol) was dissolved in anhydrous THF (400 mL) and stirred at −78°C. under nitrogen To this was added 1.5 eq of a 2.0M THF solution ofsodium bis(trimethylsilyl)amide dropwise over 5 minutes. The lightyellow mixture was stirred for 20 minutes under nitrogen at −78° C.,followed by the slow dropwise addition of oxaziridine (53 g, 180 mmol)as a 200 mL solution in THF. The mixture was stirred for 0.5 hour. Thereaction was quenched with saturated aqueous NH₄Cl, and the mixture wasextracted with EtOAc (1 L). The extract was washed with 1N HCl (1 L),dried over MgSO₄, and concentrated to a 500 mL volume. The precipitatedwhite solid was filtered, the filtrate was concentrated to removesolvent after the addition of silica gel (200 g). The residue was put ona column (8×80 cm) of silica gel (900 g), which was previously packed inhexanes. Elution was carried out initially with DCM:hexanes (1:1). Oncethe oxaziridine and imine were completely collected, the column waseluted with DCM to obtain(3R,5R)-5-Biphenyl-4-ylmethyl-1-(2,2-dimethylpropionyl)-3-hydroxypyrrolidin-2-one(21 g, 98% purity) as yellow oil.

(3R,5R)-5-Biphenyl-4-ylmethyl-1-(2,2-dimethylpropionyl)-3-hydroxypyrrolidin-2-one(56 g, 0.156 mol) was dissolved in EtOH (700 mL) and 12N HCl (700 mL).The mixture was heated to 90-95° C. for 20 hours. The mixture wasconcentrated on an 80° C. water bath under reduced pressure. EtOH (100mL) was added to the residue, and the resulting mixture was filtered toyield a yellow solid. This solid was suspended in 3N HCl/EtOH (800 mL).The mixture was refluxed for 3 hours. The solution was concentrated to areduced volume (˜200 mL volume), and ether (200 mL) was added. Theresulting slightly yellow solid was filtered and dried under reducedpressure to yield (2R,4R)-4-amino-5-biphenyl-4-yl-2-hydroxypentanoicacid ethyl ester (43 g).

Preparation 4 (2R,4R)-4-Amino-5-biphenyl-4-yl-2-hydroxypentanoic AcidButyl Ester

1-Butanol (40 mL, 400 mmol) was cooled in an ice bath and acetylchloride was added dropwise until a concentration of 4N HCl wasachieved. The mixture was warmed to room temperature.(2R,4R)-4-amino-5-biphenyl-4-yl-2-hydroxypentanoic acid ethyl ester (HClsalt; 250 mg, 710 μmol) was added to the acidified butanol (15 mL) andthe mixture was capped and heated to 80° C. for 3 hours. The resultingproduct was dried under vacuum to yield the title compound as awhite/orange flaky solid HCl salt (220 mg).

Example 1

A.(2R,4R)-4-[(5-Acetyl-2H-pyrazole-3-carbonyl)amino]-5-biphenyl-4-yl-2-hydroxypentanoicAcid Ethyl Ester (R⁷=—CH₂CH₃)

(2R,4R)-4-Amino-5-biphenyl-4-yl-2-hydroxypentanoic acid ethyl ester (HClsalt; 500 mg, 1 mmol, 1.0 eq.), 5-acetyl-2H-pyrazole-3-carboxylic acid(330.4 mg, 2.1 mmol, 1.5 eq.), and HATU (820 mg, 2.1 mmol, 1.5 eq.) werecombined in DMF (5 mL), and the resulting mixture was stirred for 2minutes. DIPEA (750 μL) was added and the mixture was stirred for 1hour. The mixture was dried under vacuum, and the product was purifiedusing reverse phase chromatography (10-70% MeCN/H₂O; 0.05% TFA over 70minutes) to yield the title compound (300 mg, purity 98%) as a TFA salt.MS m/z [M+H]⁺ calc'd for C₂₅H₂₇N₃O₅, 450.20; found 450.2.

B.(2R,4R)-4-[(5-Acetyl-2H-pyrazole-3-carbonyl)amino]-5-biphenyl-4-yl-2-hydroxypentanoicAcid (R⁷=H)

A portion (200 mg) of the purified ethyl ester (compound A) wasdissolved in EtOH (˜10 mL), and 10N NaOH was added to make the solutionbasic (˜200 μL). The mixture was monitored over 1 hour until finaldeprotection was complete. The mixture was acidified with an equalvolume (˜200 μL) of AcOH and dried under vacuum. The product waspurified using reverse phase chromatography to yield the title compoundas a TFA salt (160 mg; purity 100%). MS m/z [M+H]⁺ calc'd forC₂₃H₂₃N₃O₅, 422.16; found 422.2.

C.(2R,4R)-4-[(5-Acetyl-2H-pyrazole-3-carbonyl)amino]-5-biphenyl-4-yl-2-hydroxypentanoicAcid Butyl Ester (R⁷=—(CH₂)₃CH₃)

(2R,4R)-4-Amino-5-biphenyl-4-yl-2-hydroxypentanoic acid butyl ester (HClsalt; 500 mg, 1 mmol, 1.0 eq.), 3-acetyl-1H-pyrazole-5-carboxylic acid(330.4 mg, 2.1 mmol, 1.5 eq.), and HATU (820 mg, 2.1 mmol, 1.5 eq.) werecombined in DMF (5 mL), and the resulting mixture was stirred for 2minutes. DIPEA (750 μL) was added and the mixture was stirred for 1hour. The mixture was dried under vacuum, and the product was purifiedusing reverse phase chromatography to yield the title compound as a TFAsalt (45 mg; purity 95%). MS m/z [M+H]⁺ calc'd for C₂₇H₃₁N₃O₅, 478.23;found 478.4.

D.(2R,4R)-4-[(5-Acetyl-2H-pyrazole-3-carbonyl)amino]-5-biphenyl-4-yl-2-hydroxypentanoicAcid 2-methoxyethyl Ester (R⁷=—(CH₂)₂OCH₃)

A saturated HCl solution in 2-methoxyethanol was prepared by addingacetyl chloride (˜400 μL) dropwise to 10 mL of the anhydrous alcohol. Tothis solution was added(2R,4R)-4-[(5-acetyl-2H-pyrazole-3-carbonyl)amino]-5-biphenyl-4-yl-2-hydroxypentanoicacid ethyl ester (21.3 mg, 47.4 μmol) and the resulting mixture washeated to 60° C. for 1-2 hours. The material was dried under vacuum. Theproduct was then purified using reverse phase chromatography to yieldthe title compound as a TFA salt (10 mg; purity 100%) MS m/z [M+H]⁺calc'd for C₂₆H₂₉N₃O₆, 480.21; found 480.4.

E.(2R,4R)-4-[(5-Acetyl-2H-pyrazole-3-carbonyl)amino]-5-biphenyl-4-yl-2-hydroxypentanoicAcid 5-methyl-2-oxo-[1,3]dioxol-4-ylmethyl Ester(R⁷=—CH₂-5-methyl-[1,3]dioxol-2-one)

(2R,4R)-4-[(5-Acetyl-2H-pyrazole-3-carbonyl)amino]-5-biphenyl-4-yl-2-hydroxypentanoicacid (20 mg, 50 μmol) was dissolved in dry DMF (2 mL). Dicesiumcarbonate (50 mg, 0.2 mmol) was added, and the resulting mixture wasstirred at 0° C. for 1 hour. 4-Chloromethyl-5-methyl-1, 3-dioxol-2-one(20 mg, 0.1 mmol) was added and the resulting mixture was stirred atroom temperature overnight. EtOAc (20 mL) was added and the mixture waswashed with saturated aqueous NaCl (100 mL) then dried under vacuum. Thematerial was purified using reverse phase chromatography to yield thetitle compound as a TFA salt (5 mg, purity 100%). MS m/z [M+H]⁺ calc'dfor C₂₈H₂₇N₃O₈, 534.18; found 534.4.

F.(2R,4R)-4-[(5-Acetyl-2H-pyrazole-3-carbonyl)amino]-5-biphenyl-4-yl-2-hydroxypentanoicAcid 2-Morpholin-4-yl-ethyl Ester (R⁷=—(CH₂)₂-morpholine)

(2R,4R)-4-[(5-Acetyl-2H-pyrazole-3-carbonyl)amino]-5-biphenyl-4-yl-2-hydroxypentanoicacid (50 mg, 120 μmol, 1.1 eq.) and HATU (42 mg, 110 μmol, 1.0 eq.) werecombined in DMF (5 mL) and the resulting mixture was stirred for 2minutes. 4-Morpholineethanol (73 mg, 560 μmol, 5.0 eq.) was added,followed by the addition of DIPEA. The resulting mixture was stirred for1 hour, then the material was dried under vacuum. The product was thenpurified using reverse phase chromatography to yield the title compoundas a TFA salt (approximately 4 mg, purity 95%). MS m/z [M+H]⁺ calc'd forC₂₉H₃₄N₄O₆, 535.25; found 535.4.

G.(2R,4R)-4-[(5-Acetyl-2H-pyrazole-3-carbonyl)amino]-5-biphenyl-4-yl-2-hydroxypentanoicacid 2-Methanesulfonylethyl Ester (R⁷=—(CH₂)₂—SO₂—CH₃)

2-(Methylsulfonyl)ethanol (690 mg, 5.6 mmol) was warmed to 40° C. and0.5 eq of acetyl chloride was added with stirring for 5 minutes.(2R,4R)-4-[(5-Acetyl-2H-pyrazole-3-carbonyl)amino]-5-biphenyl-4-yl-2-hydroxypentanoicacid ethyl ester (50 mg, 110 μmol) was added and the reaction vessel wascapped and heated to 70° C. for 2 hours. The product was then purifiedusing reverse phase chromatography to yield the title compound as a TFAsalt (approximately 28 mg, purity 95%). MS m/z [M+H]⁺ calc'd forC₂₆H₂₉N₃O₇S, 528.17; found 528.4.

Preparation 5 Acetoxy(diethoxyphosphoryl)acetic Acid Ethyl Ester

Ethyl 2-oxoacetate (50%) (74 g, 724.8 mmol, 1.0 eq.) was added dropwisewith stirring at 0° C. to a solution of diethyl hydrogen phosphite (50g, 362.1 mmol, 1.0 eq.) in toluene (100 mL), under nitrogen. Et₃N (110g, 1.1 mol, 3.0 eq.) was added dropwise with stirring at 0° C. Theresulting solution was stirred for 1 hour at room temperature. To themixture was added acetic anhydride (37 g, 362.4 mmol, 1.0 eq.) dropwisewith stirring at 0° C. The resulting solution was stirred overnight atroom temperature. The pH value of the solution was adjusted to 6 with 2NHCl. The resulting solution was extracted with DCM (3×150 mL) and theorganic layers were combined, dried over Na₂SO₄, and concentrated undervacuum. The residue was loaded onto a silica gel column withEtOAc:hexanes (1:2˜1:5) to yield the title compound (52 g) as a lightyellow liquid.

Preparation 6[(R)-2-Biphenyl-4-yl-1-(methoxymethylcarbamoyl)ethyl]carbamic Acidt-Butyl Ester

Step 1: N-t-Boc-D-tyrosine (80.0 g, 284.4 mmol, 1.0 eq.), O,N-dimethyl-hydroxylamine hydrochloride (33.3 g, 341.4 mmol, 1.2 eq.),1-ethyl-3-((3-dimethylamino)-propyl)carbodiimide hydrochloride (81.8 g,426.7 mmol, 1.5 eq.), hydroxybenzotriazole (57.6 g, 426.4 mmol, 1.5eq.), and DCM (dried) (800 mL) were combined with stirring undernitrogen. The resulting mixture was cooled to 0° C. and Et₃N (44.0 g,434.8 mmol, 1.53 eq.) was added dropwise with stirring over 40 minutes.The resulting solution was stirred overnight at room temperature, thenwashed with saturated aqueous NaHCO₃ solution (2×300 mL). The organiclayer was separated and the aqueous layer was re-extracted with DCM (200mL). The organic phase was combined, dried over Na₂SO₄, and concentratedunder vacuum to yield crude compound 1 (100 g) as a yellow solid.

Step 2: Compound 1 (100.0 g, crude, 308.3 mmol, 1.0 eq.), pyridine (61.0g, 771.2 mmol, 2.5 eq.), and DCM (dried) (1000 mL) were combined withstirring under nitrogen. The resulting mixture was cooled to −20° C. andthen trifluoromethanesulfonic anhydride (104.0 g, 368.6 mmol, 1.2 eq.)was added dropwise with stirring at −20° C. over 30 minutes. Theresulting solution was then stirred for 30 minutes at −20˜−15° C. Thereaction was then quenched by the addition of water (250 mL). Theresulting mixture was washed with a 0.5N NaOH solution (2×300 mL) and a15% citric acid solution (2×300 mL). The basic aqueous layer wasre-extracted with DCM (200 mL), and the organic phase was combined,dried over Na₂SO₄, and concentrated under vacuum. The residue was loadedonto a silica gel column with EtOAc:hexanes (0˜1:5) to yield compound 2(97.7 g) as pale-yellow oil.

Step 3: Phenylboronic acid (53.0 g, 434.7 mmol, 2.03 eq.), potassiumcarbonate (45.0 g, 325.6 mmol, 1.52 eq.),tetrakis(triphenylphosphine)palladium(0) (12.5 g, 10.8 mmol, 0.05 eq.),and toluene (distilled) (800 mL) were combined with stirring undernitrogen. The resulting suspension was degassed and heated to 80° C.before adding a 200 mL toluene solution of compound 2 (97.7 g, 214.1mmol, 1.0 eq.). The thick suspension was stirred overnight at 80° C. Thereaction progress was monitored by LCMS, which indicated an incompletereaction. After the crude product/starting material mixture wasrecovered by chromatography, additional phenylboronic acid (21.2 g),potassium carbonate (18.0 g), tetrakis(triphenylphosphine)palladium(0)(5.0 g) was added and the resulting mixture suspended in toluene(distilled) (700 mL). The resulting mixture was heated to 80° C. andstirred overnight. Upon completion, the reaction was quenched by theaddition of water (300 mL). The mixture was extracted with EtOAc (2×300mL) and the organic layers were combined. The organic phase was washedwith saturated aqueous NaCl (1×300 mL), dried over Na₂SO₄, andconcentrated under vacuum. The residue was loaded onto a silica gelcolumn with EtOAc:hexanes (0˜1:3) to yield the title compound (50.0 g)as a white solid.

Preparation 7 ((R)-2-Biphenyl-4-yl-1-formylethyl)carbamic Acid t-ButylEster

[(R)-2-Biphenyl-4-yl-1-(methoxymethylcarbamoyl)ethyl]carbamic acidt-butyl ester (7.5 g, 19.5 mmol, 1.0 eq.) was combined with THF(distilled) (100 mL) under nitrogen. Lithium aluminum hydride (750 mg,19.8 mmol, 1.0 eq.) was added to the resulting stirred solution inseveral batches at −5˜0° C. over a period of 30 minutes. The resultingsolution was stirred for 30 minutes at −5-0° C. The reaction was thenquenched by the addition of a solution of KHSO₄ (6.6 g) in water (35mL). The resulting solution was combined with a 1N HCl (75 mL) solution,and stirred for five minutes. EtOAc (100 mL) was added and the resultingsolution was extracted with EtOAc (3×100 mL) and the organic layers werecombined to yield the title compound (6.3 g) as a yellow oil.

Preparation 8 (R)-4-Amino-5-biphenyl-4-yl-2-hydroxypentanoic Acid EthylEster

Step 1: A solution of acetoxy(diethoxyphosphoryl)acetic acid ethyl ester(15.6 g, 55.3 mmol, 1.2 equiv) in THF (dried) (150 mL), under nitrogen,was cooled to −78° C. LiHMDS (1M in THF) (55.3 mL, 1.2 eq.) was addeddropwise with stirring at −78° C. After stirring for 30 minutes at thattemperature, a solution of ((R)-2-biphenyl-4-yl-1-formylethyl)carbamicacid t-butyl ester (15.0 g, crude, 1.0 eq.) in THF (dried) (30 mL) wasadded dropwise over 15 minutes. Stirring was continued for 1.5 hours at−78° C. before the mixture was poured into a cold solution with water(200 mL) and EtOAc (200 mL). The organic layer was repeatedly separatedand the aqueous layer was reextracted with EtOAc (2×100 mL). Thecombined organic layers were dried over Na₂SO₄, filtered, andevaporated, and the residue was purified by flash chromatography(EtOAc/hexanes=0˜1:10) to give compound 1 (10.5 g) as a white solid.

Step 2: A stirred solution of compound 1 (10.5 g, 23.2 mmol, 1.0 eq.) inEtOH (anhydrous) (100 mL) was combined with palladium carbon (1.0 g),under nitrogen. The mixture was purged four times with hydrogen and thenhydrogen was bubbled over 2 hours at room temperature. The palladiumcarbon was filtered out, and the filtrate was concentrated under vacuumto yield crude compound 2 (10.0 g) as a pale-yellow oil, which was usedwithout further purification.

Step 3: Compound 2 (10.0 g, 22.0 mmol, 1.0 eq.) in EtOH (anhydrous) (100mL) was combined with potassium carbonate (6.1 g, 44.1 mmol, 2.0 eq.)and the resulting solution was stirred for 2 hours at room temperature.The solids were filtered out and the filtrate was concentrated undervacuum. The residue was loaded onto a silica gel column(EtOAc/hexanes=0˜1:5) to yield compound 3 (6.0 g) as a white solid.

Step 4: Compound 3 (6.0 g, 14.5 mmol, 1.0 eq.) was dissolved in DCM(dried) (120 mL), and HCl was bubbled into the mixture over 5-6 hours atroom temperature. Solid precipitate was observed. The mixture wasconcentrated to half volume then filtered. The solids were collected andwashed with cold EtOAc, and dried over reduced pressure to yield thetitle compound (4.2 g) as an off-white solid HCl salt. LC-MS (ES, m/z):314 [M−HCl+H]⁺.

¹H NMR (300 MHz, DMSO): δ (ppm)=8.07 (s, 1.9H), 7.96 (s, 1.2H),7.65-7.69 (m, 4.0H), 7.45-7.50 (m, 2.0H), 7.33-7.39 (m, 3.0H), 6.05-6.07(m, 0.63H), 5.88-5.90 (m, 0.88H), 4.32-4.38 (m, 0.80H), 4.18-4.31 (m,0.51H), 4.05-4.11 (m, 2H), 3.50 (s, 1H), 2.75-3.05 (m, 2.8H), 1.83-1.94(m, 1H), 1.71-1.82 (m, 1H), 1.10-1.20 (m, 3.3H).

Example 2

A.5-((1R,3S)-1-Biphenyl-4-ylmethyl-3-ethoxycarbonyl-3-hydroxypropylcarbamoyl)-2H-pyrazole-3-carboxylicAcid (R⁷=—CH₂CH₃) B.5-((1R,3R)-1-Biphenyl-4-ylmethyl-3-hydroxypropylcarbamoyl)-2H-pyrazole-3-carboxylicAcid (R⁷=—CH₂CH₃) C.5-((1R,3S)-1-Biphenyl-4-ylmethyl-3-carboxy-3-hydroxypropylcarbamoyl)-2H-pyrazole-3-carboxylicAcid (R⁷=H) D.5-((1R,3R)-1-Biphenyl-4-ylmethyl-3-carboxy-3-hydroxypropylcarbamoyl)-2H-pyrazole-3-carboxylicAcid (D; R⁷=H)

(R)-4-Amino-5-biphenyl-4-yl-2-hydroxypentanoic acid ethyl ester (500 mg,1.6 mmol, 1.0 eq.), 3,5-pyrazoledicarboxylic acid (250 mg, 1.6 mmol, 1.6eq.), and HATU (610 mg, 1.6 mmol, 1.0 eq.) were combined in DMF (5 mL),and the resulting mixture was stirred for 2 minutes. DIPEA (1 mL) wasadded and the mixture was stirred for 1 hour. The mixture was driedunder vacuum, and the product was purified using reverse phasechromatography (10-70% MeCN/H₂O; 0.05% TFA over 70 minutes) to yield5-((R)-1-biphenyl-4-ylmethyl-3-ethoxycarbonyl-3-hydroxypropylcarbamoyl)-2H-pyrazole-3-carboxylicacid as a TFA salt.

This material was separated by preparative HPLC, purified using reversephase chromatography and dried under vacuum to yield compounds A and Bas TFA salts. Compounds A and B were each dissolved in EtOH (˜100 mL),and 10N NaOH was added to make the solutions basic (˜200 μL). Eachmixture was monitored over 1 hour until final deprotection was complete.Each mixture was acidified with an equal volume (˜200 μL) of AcOH anddried under vacuum. The products were purified using reverse phasechromatography to yield compound C (52 mg; purity 100%; MS m/z [M+H]⁺calc'd for C₂₂H₂₁N₃O₆, 424.14; found 424.2) and compound D (65 mg;purity 100%; MS m/z [M+H]⁺ calc'd for C₂₂H₂₁N₃O₆, 424.14; found 424.2)as TFA salts.

E.5-((1R,3R)-1-Biphenyl-4-ylmethyl-3-butoxycarbonyl-3-hydroxy-propylcarbamoyl)-1H-pyrazole-3-carboxylicAcid (R⁷=—(CH₂)₃CH₃)

(2R,4R)-4-Amino-5-biphenyl-4-yl-2-hydroxypentanoic acid butyl ester (HClsalt; 108 mg, 286 μmmol, 1.0 eq.), 3,5-pyrazoledicarboxylic acid (66.9mg, 429 μmol, 1.5 eq.), and HATU (160 mg, 430 μmol, 1.5 eq.) werecombined in DMF (5 mL), and the resulting mixture was stirred for 2minutes. DIPEA (150 μL) was added and the mixture was stirred for 1hour. The mixture was dried under vacuum, and the product was purifiedusing reverse phase chromatography to yield the title compound as a TFAsalt (60 mg; purity 98%). MS m/z [M+H]⁺ calc'd for C₂₆H₂₉N₃O₆, 480.21;found 480.4).

Example 3

A.(2S,4R)-5-Biphenyl-4-yl-2-hydroxy-4-({5-[(2-methoxyethyl)methylcarbamoyl]-2H-pyrazole-3-carbonyl}amino)pentanoicAcid Ethyl Ester (R⁷=—CH₂CH₃) B.(2R,4R)-5-Biphenyl-4-yl-2-hydroxy-4-({5-[(2-methoxyethyl)methylcarbamoyl]-2H-pyrazole-3-carbonyl}amino)pentanoicAcid Ethyl Ester (R⁷=—CH₂CH₃) C.(2S,4R)-5-Biphenyl-4-yl-2-hydroxy-4-({5-[(2-methoxyethyl)methylcarbamoyl]-2H-pyrazole-3-carbonyl}amino)pentanoicAcid (R⁷=H) D.(2R,4R)-5-Biphenyl-4-yl-2-hydroxy-4-({5-[(2-methoxyethyl)methylcarbamoyl]-2H-pyrazole-3-carbonyl}amino)pentanoicAcid (R⁷=H)

(R)-4-Amino-5-biphenyl-4-yl-2-hydroxypentanoic acid ethyl ester (900 mg,3.0 mmol, 1.0 eq.), 3,5-pyrazoledicarboxylic acid (448 mg, 2.9 mmol, 1.0eq.), N-(2-methoxyethyl)methylamine (256 mg, 2.9 mmol, 1.0 eq.), andHATU (1090 mg, 2.9 mmol, 1.0 eq.) were combined in DMF (5 mL), and theresulting mixture was stirred for 2 minutes. DIPEA (1 mL) was added andthe mixture was stirred for 1 hour. The mixture was dried under vacuum,and the product was purified using reverse phase chromatography (10-70%MeCN/H₂O; 0.05% TFA over 70 minutes) to yield(R)-5-biphenyl-4-yl-2-hydroxy-4-({5-[(2-methoxyethyl)methylcarbamoyl]-2H-pyrazole-3-carbonyl}amino)-pentanoicacid ethyl ester (25 mg) as a TFA salt.

This material was separated by preparative HPLC, purified using reversephase chromatography and dried under vacuum to yield compounds A and Bas TFA salts. Compounds A and B were each dissolved in EtOH (˜10 mL),and 10N NaOH was added to make the solutions basic (˜200 μL). Eachmixture was monitored over 1 hour until final deprotection was complete.Each mixture was acidified with an equal volume (˜200 μL) of AcOH anddried under vacuum. The products were purified using reverse phasechromatography to yield compounds C (20.6 mg; purity 100%; MS m/z [M+H]⁺calc'd for C₂₆H₃₀N₄O₆, 495.22; found 495.22) and D (8.3 mg; purity 100%;MS m/z [M+H]⁺ calc'd for C₂₆H₃₀N₄O₆, 495.22; found 495.22) as TFA salts.

Example 4

A.(2R,4R)-4-{[5-(Azetidine-1-carbonyl)-2H-pyrazole-3-carbonyl]amino}-5-biphenyl-4-yl-2-hydroxypentanoicAcid Ethyl Ester (R⁷=—CH₂CH₃)

(2R,4R)-4-Amino-5-biphenyl-4-yl-2-hydroxypentanoic acid ethyl ester (HClsalt; 100 mg, 286 μmol, 1.0 eq.), 3,5-pyrazoledicarboxylic acid (66.9mg, 429 μmol, 1.5 eq.), and HATU (160 mg, 430 μmol, 1.5 eq.) werecombined in DMF (5 mL), and the resulting mixture was stirred for 2minutes. DIPEA (150 μL) was added and the mixture was stirred for 1hour. Azetidine hydrochloride (40.0 mg, 429 μmol, 1.5 eq.) was addedwith a second equivalent of HATU, and the mixture was stirred briefly.Additional DIPEA (2.0 eq.) was added and the mixture was stirred. Themixture was dried under vacuum then purified using reverse phasechromatography (10-70% MeCN/H₂O; 0.05% TFA over 70 minutes) to yield thetitle compound as a TFA salt (20 mg; purity 95%). MS m/z [M+H]⁺ calc'dfor C₂₇H₃₀N₄O₅, 491.22; found 491.4.

B.(2R,4R)-4-{[5-(Azetidine-1-carbonyl)-2H-pyrazole-3-carbonyl]amino}-5-biphenyl-4-yl-2-hydroxy-pentanoicacid (R⁷=H)

(2R,4R)-4-Amino-5-biphenyl-4-yl-2-hydroxypentanoic acid ethyl ester (HClsalt; 50 mg, 0.1 mmol, 1.0 eq.), 3,5-pyrazoledicarboxylic acidmonohydrate (29.9 mg, 173 mol, 1.2 eq.), and HATU (82 mg, 210 μmol, 1.5eq.) were combined in DMF (5 mL), and the resulting mixture was stirredfor 2 minutes. DIPEA (75 μL) was added and the mixture was stirred for 1hour. Azetidine hydrochloride (20.0 mg, 214 μmol, 1.5 eq.) was addedwith a second equivalent of HATU, and the mixture was stirred briefly.The mixture was dried under vacuum to yield the crude ester. The crudeester was dissolved in EtOH (˜10 mL), and 10N NaOH was added to make thesolution basic (˜200 μL). The mixture was monitored over 1 hour untilfinal deprotection was complete. The mixture was acidified with an equalvolume (˜200 μL) of AcOH and dried under vacuum. The product waspurified using reverse phase chromatography to yield the title compoundas a TFA salt (17 mg; purity 95%). MS m/z [M+H]⁺ calc'd for C₂₅H₂₆N₄O₅,463.19; found 463.4.

Example 5

A.(2R,4R)-5-Biphenyl-4-yl-2-hydroxy-4-{[5-(pyrrolidine-1-carbonyl)-2H-pyrazole-3-carbonyl]amino}pentanoicAcid Ethyl Ester (R⁷=—CH₂CH₃)

(2R,4R)-4-Amino-5-biphenyl-4-yl-2-hydroxypentanoic acid ethyl ester (HClsalt; 85 mg, 240 μmol, 1.0 eq.), 3,5-pyrazoledicarboxylic acidmonohydrate (40 mg, 0.2 mmol, 1.0 eq.), and HATU (90 mg, 0.2 mmol, 1.0eq.) were combined in DMF (5 mL), and the resulting mixture was stirredfor 2 minutes. DIPEA (150 μL) was added and the mixture was stirred for1 hour. A second equivalent of HATU was added, followed by pyrrolidine(20.3 μL, 243 μmol, 1.0 eq.) (1N in THF) and a second equivalent ofDIPEA. Upon completion of the reaction, the mixture was dried undervacuum then purified using reverse phase chromatography (10-70%MeCN/H₂O; 0.05% TFA over 70 minutes) to yield the title compound as aTFA salt (65 mg; purity 98%). MS m/z [M+H]⁺ calc'd for C₂₈H₃₂N₄O₅,505.24; found 505.4.

B.(2R,4R)-5-Biphenyl-4-yl-2-hydroxy-4-{[5-(pyrrolidine-1-carbonyl)-2H-pyrazole-3-carbonyl]-amino}pentanoicAcid (R⁷=H)

(2R,4R)-4-Amino-5-biphenyl-4-yl-2-hydroxypentanoic acid ethyl ester (HClsalt; 50 mg, 0.1 mmol, 1.0 eq.), 3,5-pyrazoledicarboxylic acidmonohydrate (20.0 mg, 0.1 mmol, 1.0 eq.), and HATU (50 mg, 0.1 mmol, 1.0eq.) were combined in DMF (5 mL), and the resulting mixture was stirredfor 2 minutes. DIPEA (75 μL) was added and the mixture was stirred for 1hour. A second equivalent of HATU was added, followed by pyrrolidine(20.0 mg, 280 μmol, 2.0 eq.) and a second equivalent of DIPEA. Themixture was dried under vacuum to yield the crude ester. The crude esterwas dissolved in EtOH (˜10 mL), and 10N NaOH was added to make thesolution basic (˜200 μL). The mixture was monitored over 1 hour untilfinal deprotection was complete. The mixture was acidified with an equalvolume (˜200 μL) of AcOH and dried under vacuum. The product waspurified using reverse phase chromatography to yield the title compoundas a TFA salt (25 mg; purity 95%). MS m/z [M+H]⁺ calc'd for C₂₆H₂₈N₄O₅,477.21; found 477.0.

Example 6

A.(2R,4R)-5-Biphenyl-4-yl-2-hydroxy-4-[(2-hydroxypyrimidine-5-carbonyl)amino]pentanoicAcid Ethyl Ester (R⁷=—CH₂CH₃) B.(2R,4R)-5-Biphenyl-4-yl-2-hydroxy-4-[(2-hydroxypyrimidine-5-carbonyl)amino]pentanoicAcid (R⁷=H)

(2R,4R)-4-Amino-5-biphenyl-4-yl-2-hydroxypentanoic acid ethyl ester (HClsalt; 200 mg, 572 μmol, 1.0 eq.) and 2-hydroxypyrimidine-5-carboxylicacid (88.1 mg, 629 mol) were suspended in DMF (5.0 mL). HATU (239 mg,629 μmol) was added followed by DIPEA (299 μL), and the resultingmixture was stirred at room temperature until the reaction was complete(˜2 hours). The mixture was divided into two equal portions and bothsolutions were concentrated. One portion was purified by preparativeHPLC (10-70% MeCN/H₂O) to produce compound A as a TFA salt (59.2 mg). MSm/z [M+H]⁺ calc'd for C₂₄H₂₅N₃O₅, 436.18; found 436.4. The remainingportion was dissolved in THF (2.0 mL). LiOH monohydrate (120 mg, 2.9mmol) in water (2.0 mL) was added and the mixture was stirred at roomtemperature for ˜1 hour. The reaction was quenched by addition of AcOHand the solution was concentrated. The crude product was purified bypreparative HPLC (10-70% MeCN/H₂O) to yield compound B as a TFA salt(27.8 mg). MS m/z [M+H]⁺ calc'd for C₂₂H₂₁N₃O₅, 408.15; found 408.4.

Example 7

A.(2R,4R)-5-Biphenyl-4-yl-2-hydroxy-4-[(3-hydroxyisoxazole-5-carbonyl)amino]pentanoicAcid Ethyl Ester (R⁷=—CH₂CH₃)

3-Hydroxyisoxazole-5-carboxylic acid (81.2 mg, 629 μmol, 1.1 eq.) wasdissolved in DMF (5.0 mL). DIPEA (299 μL) and HOAt (85.6 mg, 629 μmol,1.1 eq.) were added, followed by EDCI (111 μL, 1.1 eq.). The solutionwas stirred for 5 minutes.(2R,4R)-4-Amino-5-biphenyl-4-yl-2-hydroxypentanoic acid ethyl ester (HClsalt; 200 mg, 572 μmol, 1.0 eq.) was then added and the resultingmixture were stirred at room temperature overnight. The mixture wasconcentrated, and the crude product was purified by preparative HPLC(10-70% MeCN/H₂O) to yield the title compound as a TFA salt (50.8 mg,98% purity). MS m/z [M+H]⁺ calc'd for C₂₃H₂₄N₂O₆, 425.16; found 425.4.

B.(2R,4R)-5-Biphenyl-4-yl-2-hydroxy-4-[(3-hydroxyisoxazole-5-carbonyl)amino]pentanoicAcid (R⁷=H)

(2R,4R)-4-Amino-5-biphenyl-4-yl-2-hydroxypentanoic acid ethyl ester (HClsalt; 200 mg, 572 μmol, 1.0 eq.) and 3-hydroxyisoxazole-5-carboxylicacid (81.2 mg, 629 mol) were suspended in DMF (5.0 mL). HATU (239 mg,629 μmol) was added followed by DIPEA (299 μL), and the resultingmixture was stirred at room temperature overnight. The mixture wasconcentrated and the crude compound was used without purification. Thecrude material was dissolved in THF (3.0 mL). LiOH monohydrate (240 mg,5.7 mmol) in water (3.0 mL) was added and the mixture was stirred atroom temperature for ˜1 hour. The mixture was concentrated and the crudeproduct was purified by preparative HPLC (10-70% MeCN/H₂O) to yield thetitle compound as a TFA salt (36.6 mg, 97% purity). MS m/z [M+H]⁺ calc'dfor C₂₁H₂₀N₂O₆, 397.13; found 397.2.

C.(2R,4R)-5-Biphenyl-4-yl-2-hydroxy-4-[(3-hydroxyisoxazole-5-carbonyl)amino]pentanoicacid 5-methyl-2-oxo-[1,3]dioxol-4-ylmethyl Ester(R⁷=—CH₂-5-methyl-[1,3]dioxol-2-one)

(2R,4R)-4-Amino-5-biphenyl-4-yl-2-hydroxy-pentanoic acid ethyl ester;hydrochloride (1.6 g, 4.6 mmol, 1.0 eq.) was dissolved in DCM (100 mL)and cooled to 0° C. Di-t-butyldicarbonate (1.2 g, 5.4 mmol, 1.2 eq.) wasadded as a solid followed by DIPEA (1.6 mL, 9.1 mmol). The resultingmixture was stirred overnight at room temperature. The product waspurified by flash chromatography (0˜75% EtOAc/hexanes) then dissolved inEtOH and sufficient equivalents of 10N NaOH to make the solution basic(pH=14). The reaction was monitored until deprotection was complete (˜1hour). EtOAc (200 mL) was added and the mixture was washed with 1N HCl(100 mL) followed by saturated aqueous NaCl (100 mL). The organic layerwas retained and dried over anhydrous MgSO₄ for 10 minutes prior tofiltration and evacuation to dryness, to yield(2R,4R)-5-biphenyl-4-yl-4-t-butoxycarbonylamino-2-hydroxypentanoic acid(1.2 g).

(2R,4R)-5-Biphenyl-4-yl-4-t-butoxycarbonylamino-2-hydroxypentanoic acid(500 mg, 1.0 mmol, 1.0 eq.) was dissolved in dry DMF (10.0 mL). Thesolution was cooled to 0° C. and dicesium carbonate (465 mg, 1.4 mmol,1.1 eq.) was added. The mixture was stirred for 30 minutes and4-chloromethyl-5-methyl-1,3-dioxol-2-one (212 mg, 1.4 mmol, 1.1 eq.) wasadded. The resulting mixture was stirred for an additional 1 hour at 0°C., then warmed to room temperature while stirring. The mixture wasfurther stirred overnight. EtOAc (20 mL) was added, followed by washingwith saturated aqueous NaCl (100 mL). The product was dried under vacuumand purified using reverse phase chromatography (10-70% MeCN/H₂O; 0.05%TFA over 70 minutes) to yield(2R,4R)-5-biphenyl-4-yl-4-t-butoxycarbonylamino-2-hydroxypentanoic acid5-methyl-2-oxo-[1,3]dioxol-4-ylmethyl ester. This material was dissolvedin 4N HCL in dioxane and stirred for 2 hours at room temperature. Thematerial was dried under vacuum then azeotroped with toluene to yield(2R,4R)-4-amino-5-biphenyl-4-yl-2-hydroxypentanoic acid5-methyl-2-oxo-[1,3]dioxol-4-ylmethyl ester, which was used in the nextstep without further purification.

(2R,4R)-4-amino-5-biphenyl-4-yl-2-hydroxypentanoic acid5-methyl-2-oxo-[1,3]dioxol-4-ylmethyl ester (100 mg, 0.3 mmol, 1.0 eq.)and 3-hydroxyisoxazole-5-carboxylic acid (50.5 mg, 391 μmol, 1.5 eq.)were combined in DMF (5 mL) and the resulting mixture was stirred for 2minutes. DIPEA was added and the resulting mixture was stirred for 1hour. The material was dried under vacuum then purified using reversephase chromatography to yield the title compound (40 mg, 98% purity). MSm/z [M+H]⁺ calc'd for C₂₆H₂₄N₂O₉, 509.15; found 509.4.

Example 8

A.(2R,4R)-5-Biphenyl-4-yl-2-hydroxy-4-{[5-(1-hydroxy-1-methylethyl)-1H-pyrazole-3-carbonyl]amino}pentanoicacid ethyl ester (R⁷=—CH₂CH₃)

(2R,4R)-4-Amino-5-biphenyl-4-yl-2-hydroxypentanoic acid ethyl ester (HClsalt; 100 mg, 0.3 mmol, 1.0 eq.),5-(1-hydroxy-1-methylethyl)-1H-pyrazole-3-carboxylic acid (73 mg, 429μmmol, 1.5 eq.), and HATU (160 mg, 430 μmol, 1.5 eq.) were combined inDMF (5 mL), and the resulting mixture was stirred for 2 minutes. DIPEA(149 μL) was added and the mixture was stirred for 1 hour. Uponcompletion of the reaction, the mixture was dried under vacuum thenpurified using reverse phase chromatography (10-70% MeCN/H₂O; 0.05% TFAover 70 minutes) to yield the title compound as a TFA salt (50 mg). MSm/z [M+H]⁺ calc'd for C₂₆H₃₁N₃O₅, 466.23; found 466.4.

B.(2R,4R)-5-Biphenyl-4-yl-2-hydroxy-4-{[5-(1-hydroxy-1-methylethyl)-1H-pyrazole-3-carbonyl]amino}pentanoicacid (R⁷=H)

(2R,4R)-4-Amino-5-biphenyl-4-yl-2-hydroxypentanoic acid ethyl ester (HClsalt; 60 mg, 0.2 mmol, 1.0 eq.),5-(1-hydroxy-1-methylethyl)-1H-pyrazole-3-carboxylic acid (43.8 mg, 257μmol, 150 eq.), and HATU (98 mg, 260 μmol, 1.5 eq.) were combined in DMF(5 mL), and the resulting mixture was stirred for 2 minutes. DIPEA (89.6μL) was added and the mixture was stirred for 1 hour. The mixture wasdried under vacuum to yield the crude ester. The crude ester wasdissolved in EtOH (˜10 mL), and 10N NaOH was added to make the solutionbasic (˜200 μL). The mixture was monitored over 1 hour until finaldeprotection was complete. The mixture was acidified with an equalvolume (˜200 μL) of AcOH and dried under vacuum. The product waspurified using reverse phase chromatography to yield the title compoundas a TFA salt (30 mg). MS m/z [M+H]⁺ calc'd for C₂₄H₂₇N₃O₅, 438.20;found 438.4.

Example 9 2-Hydroxypyrimidine-5-carboxylic acid((1R,3R)-1-biphenyl-4-ylmethyl-3-carbamoyl-3-hydroxypropyl)amide

(2R,4R)-5-Biphenyl-4-yl-2-hydroxy-4-[(2-hydroxypyrimidine-5-carbonyl)amino]pentanoicacid (14.5 mg, 35.6 μmol, 1.0 eq.) and HATU (13.5 mg, 35.6 mol, 1.0 eq.)were combined in DMF (5 mL), and the resulting mixture was stirred for 2minutes. 0.5 M ammonia in dioxane was added, followed by DIPEA (12.4μL). The resulting mixture was stirred for 1 hour then dried undervacuum. The product was purified using reverse phase chromatography(10-70% MeCN/H₂O; 0.05% TFA over 70 minutes) to yield the title compound(2 mg). MS m/z [M+H]⁺ calc'd for C₂₂H₂₂N₄O₄, 407.16; found 407.4.

Following the procedures described in the examples herein, andsubstituting the appropriate starting materials and reagents, thecompounds in Examples 10 to 15, having the following formula, were alsoprepared:

Example 10

These were prepared as the parent compound or as a TFA salt.

MS m/z: [M + H]⁺ Ex. R¹ R³ R⁴ Formula calcd found 1 —OCH₂CH₃ H HC₂₂H₂₄N₄O₄ 409.18 409.4 2 —OH H H C₂₀H₂₀N₄O₄ 381.15 381.4

-   1.    (R)-5-Biphenyl-4-yl-2-hydroxy-4-[(3H-[1,2,3]triazole-4-carbonyl)amino]pentanoic    acid ethyl ester (TFA salt)-   2.    (2R,4R)-5-Biphenyl-4-yl-2-hydroxy-4-[(3H-[1,2,3]triazole-4-carbonyl)amino]pentanoic    acid (TFA salt)

MS m/z: [M + H]⁺ Ex. R¹ R³ R⁴ Formula calcd found 3 —OH —OH H C₂₂H₂₀N₄O₅397.14 397.0 4 —OCH₂CH₃ —OH H C₂₂H₂₄N₄O₅ 425.17 425.2

-   3.    (2R,4R)-5-Biphenyl-4-yl-2-hydroxy-4-[(1-hydroxy-1H-[1,2,3]triazole-4-carbonyl)-amino]-pentanoic    acid-   4.    (2R,4R)-5-Biphenyl-4-yl-2-hydroxy-4-[(1-hydroxy-1H-[1,2,3]triazole-4-carbonyl)-amino]-pentanoic    acid ethyl ester (TFA salt)

MS m/z: [M + H]⁺ Ex. R¹ R³ R⁴ Formula calcd found 5 —OCH₂CH₃ H HC₂₂H₂₄N₄O₄ 409.18 409.4 6 —OH H H C₂₀H₂₀N₄O₄ 381.15 381.4 7 —OH —CH₃4-chlorophenyl C₂₇H₂₅ClN₄O₄ 505.16 506.2 8 —OCH₂CH₃ —OH H C₂₂H₂₄N₄O₅425.17 425.2 9 —OH —OH H C₂₀H₂₀N₄O₅ 397.14 397.2

-   5.    (R)-5-Biphenyl-4-yl-2-hydroxy-4-[(1H-[1,2,4]triazole-3-carbonyl)amino]pentanoic    acid ethyl ester (TFA salt)-   6.    (R)-5-Biphenyl-4-yl-2-hydroxy-4-[(1H-[1,2,4]triazole-3-carbonyl)amino]pentanoic    acid (TFA salt)-   7.    (R)-5-Biphenyl-4-yl-4-{[1-(4-chlorophenyl)-5-methyl-1H-[1,2,4]triazole-3-carbonyl]-amino}-2-hydroxypentanoic    acid (TFA salt)-   8.    (2R,4R)-5-Biphenyl-4-yl-2-hydroxy-4-[(5-hydroxy-1H-[1,2,4]triazole-3-carbonyl)amino]-pentanoic    acid ethyl ester (TFA salt)-   9.    (2R,4R)-5-Biphenyl-4-yl-2-hydroxy-4-[(5-hydroxy-1H-[1,2,4]triazole-3-carbonyl)amino]-pentanoic    acid (TFA salt)

MS m/z: [M + H]⁺ Ex. R¹ R³ R⁴ Formula calcd found 10 —OH 2-pyridine HC₂₅H₂₃N₅O₄ 458.18 458.2

-   10.    (R)-5-Biphenyl-4-yl-2-hydroxy-4-[(5-pyridin-2-yl-4H-[1,2,4]triazole-3-carbonyl)amino]pentanoic    acid (TFA salt)

MS m/z: [M + H]⁺ Ex. R¹ R³ R⁴ Formula calcd found 11 —OH —CH₃ HC₂₁H₂₂N₄O₄ 395.16 395.2 12 —OH —Cl H C₂₀H₁₉ClN₄O₄ 415.11 415.4

-   11.    (R)-5-Biphenyl-4-yl-2-hydroxy-4-[(5-methyl-2H-[1,2,4]triazole-3-carbonyl)amino]pentanoic    acid (TFA salt)-   12.    (2R,4R)-5-Biphenyl-4-yl-4-[(5-chloro-2H-[1,2,4]triazole-3-carbonyl)amino]-2-hydroxypentanoic    acid

Example 11

These were all prepared as TFA salts.

MS m/z: [M + H]⁺ Ex. R¹ R³ R⁴ Formula calcd found 1 —OH H 3- C₃₂H₂₈N₄O₆565.20 565.6 carboxylbenzyl 2 —OH H 4- C₃₂H₂₈N₄O₆ 565.20 565.6carboxybenzyl 3 —OH H H C₂₄H₂₂N₄O₄ 431.16 431.2 4 —OH F H C₂₄H₂₁FN₄O₄449.15 449.0 5 —OCH₂CH₃ Cl H C₂₆H₂₅ClN₄O₄ 493.16 493.2

-   1.    3-[5-((R)-1-Biphenyl-4-ylmethyl-3-carboxy-3-hydroxypropylcarbamoyl)-benzotriazol-1-ylmethyl]-benzoic    acid-   2.    4-[5-((1R,3S)-1-Biphenyl-4-ylmethyl-3-carboxy-3-hydroxypropylcarbamoyl)-benzotriazol-1-ylmethyl]-benzoic    acid-   3.    (R)-4-[(1H-Benzotriazole-5-carbonyl)amino]-5-biphenyl-4-yl-2-hydroxypentanoic    acid-   4.    (R)-5-Biphenyl-4-yl-4-[(7-fluoro-1H-benzotriazole-5-carbonyl)amino]-2-hydroxy-pentanoic    acid-   5.    (R)-5-Biphenyl-4-yl-4-[(7-chloro-1H-benzotriazole-5-carbonyl)amino]-2-hydroxy-pentanoic    acid ethyl ester

MS m/z: [M + H]⁺ Ex. R¹ R³ R⁴ Formula calcd found 6 —OH —CH₃ HC₂₅H₂₄N₄O₄ 445.18 445.2

-   6.    (R)-5-Biphenyl-4-yl-2-hydroxy-4-[(7-methyl-3H-benzotriazole-5-carbonyl)amino]pentanoic    acid

MS m/z: [M + H]⁺ Ex. R¹ R³ R⁴ Formula calcd found 7 —OH Cl HC₂₄H₂₁ClN₄O₄ 465.13 465.0

-   7.    (R)-5-Biphenyl-4-yl-4-[(4-chloro-1H-benzotriazole-5-carbonyl)amino]-2-hydroxy-pentanoic    acid

MS m/z: [M + H]⁺ Ex. R¹ R³ R⁴ Formula calcd found 8 —OH —CH₃ HC₂₆H₂₄N₂O₅ 445.17 445.4

-   8.    (R)-5-Biphenyl-4-yl-2-hydroxy-4-[(2-methyl-benzooxazole-6-carbonyl)-amino]-pentanoic    acid

MS m/z: [M + H]⁺ Ex. R¹ R³ R⁴ Formula calcd found 9 —OH H H C₂₄H₂₂N₄O₄431.16 431.2

-   9.    (R)-5-Biphenyl-4-yl-2-hydroxy-4-[(3H-imidazo[4,5-b]pyridine-6-carbonyl)-amino]-pentanoic    acid

MS m/z: [M + H]⁺ Ex. R¹ R³ R⁴ Formula calcd found 10 —OCH₂CH₃ H HC₂₅H₂₅N₅O₄ 460.19 460.4 11 —OH H H C₂₃H₂₁N₅O₄ 432.16 432.2

-   10.    (R)-5-Biphenyl-4-yl-2-hydroxy-4-[(1H-[1,2,3]triazolo[4,5-b]pyridine-6-carbonyl)-amino]-pentanoic    acid ethyl ester-   11.    (R)-5-Biphenyl-4-yl-2-hydroxy-4-[(1H-[1,2,3]triazolo[4,5-b]pyridine-6-carbonyl)-amino]-pentanoic    acid

MS m/z: [M + H]⁺ Ex. R¹ R³ R⁴ Formula calcd found 12 —OCH₂CH₃ H HC₂₅H₂₅N₅O₄ 460.19 460.4 13 —OH H H C₂₃H₂₁N₅O₄ 432.16 432.4 14 —OCH₂CH₃ HH C₂₅H₂₅N₅O₄ 460.19 460.4 15 —OH H H C₂₃H₂₁N₅O₄ 432.16 432.4

-   12.    (2S,4R)-5-Biphenyl-4-yl-2-hydroxy-4-[(3H-[1,2,3]triazolo[4,5-b]pyridine-6-carbonyl)-amino]-pentanoic    acid ethyl ester-   13.    (2S,4R)-5-Biphenyl-4-yl-2-hydroxy-4-[(3H-[1,2,3]triazolo[4,5-b]pyridine-6-carbonyl)-amino]-pentanoic    acid-   14.    (2R,4R)-5-Biphenyl-4-yl-2-hydroxy-4-[(3H-[1,2,3]triazolo[4,5-b]pyridine-6-carbonyl)-amino]-pentanoic    acid ethyl ester-   15.    (2R,4R)-5-Biphenyl-4-yl-2-hydroxy-4-[(3H-[1,2,3]triazolo[4,5-b]pyridine-6-carbonyl)-amino]-pentanoic    acid

Example 12

These were prepared as the parent compound or as a TFA salt.

MS m/z: [M + H]⁺ Ex. R¹ R³ R⁴ Formula calcd found 1 —OH —COOH HC₂₃H₂₁NO₇ 424.13 424.0

-   1.    5-((R)-1-Biphenyl-4-ylmethyl-3-carboxy-3-hydroxypropylcarbamoyl)furan-2-carboxylic    acid (TFA salt)

MS m/z: [M + H]⁺ Ex. R¹ R³ R⁴ Formula calcd found 2 —OH —COOH HC₂₃H₂₁NO₆S 440.11 440.0

-   2.    5-((R)-1-Biphenyl-4-ylmethyl-3-carboxy-3-hydroxypropylcarbamoyl)thiophene-2-carboxylic    acid

MS m/z: [M + H]⁺ Ex. R¹ R³ R⁴ Formula calcd found 3 —OH —OCH₃ HC₂₂H₂₂N₂O₆ 411.15 411.2 4 —OH

H C₂₇H₂₃ClN₂O₅ 491.13 491.2 5 —OH

H C₂₉H₂₇N₃O₇ 530.19 530.4 6 —OH

H C₂₇H₂₃ClN₂O₅ 491.13 491.4 7 —OH

H C₂₇H₃₀N₂O₅ 463.22 463.4 8 —OH

H C₂₇H₂₃FN₂O₅ 475.16 475.0 9 —OH

H C₂₇H₂₃FN₂O₅ 475.16 475.0 10  —OH

H C₂₅H₂₄N₄O₅ 461.17 461.2 11  —OH

H C₂₇H₂₂Cl₂N₂O₅ 525.09 525.4 12  —OH

H C₂₇H₂₂Cl₂N₂O₅ 525.09 525.4 13  —OH

H C₂₈H₂₆N₂O₆ 487.18 487.2 14  —OH —COOH H C₂₂H₂₀N₂O₇ 425.13 425.2

-   3.    (2R,4R)-5-Biphenyl-4-yl-2-hydroxy-4-[(3-methoxyisoxazole-5-carbonyl)amino]-pentanoic    acid-   4.    (2R,4R)-5-Biphenyl-4-yl-4-{[3-(4-chlorophenyl)-isoxazole-5-carbonyl]-amino}-2-hydroxy-pentanoic    acid (TFA salt)-   5.    (2R,4R)-5-Biphenyl-4-yl-2-hydroxy-4-{[3-(2-methoxy-benzoylamino)-isoxazole-5-carbonyl]-amino}-pentanoic    acid (TFA salt)-   6.    (2R,4R)-5-Biphenyl-4-yl-4-{[3-(2-chlorophenyl)-isoxazole-5-carbonyl]-amino}-2-hydroxy-pentanoic    acid (TFA salt)-   7.    (2R,4R)-5-Biphenyl-4-yl-4-[(3-cyclohexyl-isoxazole-5-carbonyl)-amino]-2-hydroxy-pentanoic    acid (TFA salt)-   8.    (2R,4R)-5-Biphenyl-4-yl-4-{[3-(3-fluorophenyl)-isoxazole-5-carbonyl]-amino}-2-hydroxy-pentanoic    acid-   9.    (2R,4R)-5-Biphenyl-4-yl-4-{[3-(2-fluorophenyl)-isoxazole-5-carbonyl]-amino}-2-hydroxy-pentanoic    acid-   10.    (2R,4R)-5-Biphenyl-4-yl-2-hydroxy-4-{[3-(1-methyl-1H-pyrazol-4-yl)-isoxazole-5-carbonyl]-amino}-pentanoic    acid (TFA salt)-   11.    (2R,4R)-5-Biphenyl-4-yl-4-{[3-(2,5-dichlorophenyl)-isoxazole-5-carbonyl]-amino}-2-hydroxy-pentanoic    acid-   12.    (2R,4R)-5-Biphenyl-4-yl-4-{[3-(3,4-dichlorophenyl)-isoxazole-5-carbonyl]-amino}-2-hydroxy-pentanoic    acid-   13.    (2R,4R)-5-Biphenyl-4-yl-2-hydroxy-4-{[3-(2-methoxy-phenyl)-isoxazole-5-carbonyl]-amino}-pentanoic    acid-   14.    5-((1R,3R)-1-Biphenyl-4-ylmethyl-3-carboxy-3-hydroxy-propylcarbamoyl)-isoxazole-3-carboxylic    acid

MS m/z: [M + H]⁺ Ex. R¹ R³ R⁴ Formula calcd found 15 —OH

H C₂₈H₂₆N₂O₆ 487.18 487.4 16 —OH

H C₂₇H₂₃ClN₂O₅ 491.13 491.4 17 —OH

H C₂₇H₂₃ClN₂O₅ 491.13 491.2 18 —OH

H C₂₈H₂₆N₂O₆ 487.18 487.2 19 —OH

H C₂₆H₂₉N₃O₆ 480.21 480.2 20 —OH

H C₂₈H₂₆N₂O₆ 487.18 487.2 21 —OH

H C₂₇H₂₄N₂O₆ 473.16 473.0 22 —OH

H C₂₈H₂₄ClN₃O₆ 534.14 535.0

-   15.    (2R,4R)-5-Biphenyl-4-yl-2-hydroxy-4-{[5-(2-methoxy-phenyl)-isoxazole-3-carbonyl]-amino}-pentanoic    acid (TFA salt)-   16.    (2R,4R)-5-Biphenyl-4-yl-4-{[5-(2-chlorophenyl)-isoxazole-3-carbonyl]-amino}-2-hydroxy-pentanoic    acid (TFA salt)-   17.    (2R,4R)-5-Biphenyl-4-yl-4-{[5-(4-chlorophenyl)-isoxazole-3-carbonyl]-amino}-2-hydroxy-pentanoic    acid (TFA salt)-   18.    (2R,4R)-5-Biphenyl-4-yl-2-hydroxy-4-{[5-(3-methoxy-phenyl)-isoxazole-3-carbonyl]-amino}-pentanoic    acid (TFA salt)-   19.    (2R,4R)-5-Biphenyl-4-yl-2-hydroxy-4-[(5-morpholin-4-ylmethyl-isoxazole-3-carbonyl)-amino]-pentanoic    acid (TFA salt)-   20.    (2R,4R)-5-Biphenyl-4-yl-2-hydroxy-4-{[5-(4-methoxy-phenyl)-isoxazole-3-carbonyl]-amino}-pentanoic    acid (TFA salt)-   21.    (2R,4R)-5-Biphenyl-4-yl-2-hydroxy-4-{[5-(2-hydroxy-phenyl)-isoxazole-3-carbonyl]-amino}-pentanoic    acid (TFA salt)-   22.    (2R,4R)-5-Biphenyl-4-yl-4-{[5-(2-chlorobenzoylamino)-isoxazole-3-carbonyl]-amino}-2-hydroxy-pentanoic    acid (TFA salt)

MS m/z: [M + H]⁺ Ex. R¹ R³ R⁴ Formula calcd found 23 —OH phenyl HC₂₇H₂₄N₂O₅ 457.17 457.4

-   23.    (2R,4R)-5-Biphenyl-4-yl-2-hydroxy-4-[(2-phenyl-oxazole-5-carbonyl)-amino]-pentanoic    acid (TFA salt)

MS m/z: [M + H]⁺ Ex. R¹ R³ R⁴ Formula calcd found 24 —OH —NHC(O)CH₃ HC₂₃H₂₃N₃O₅S 454.14 454.2

-   24.    (2R,4R)-4-[(2-Acetylamino-thiazole-5-carbonyl)-amino]-5-biphenyl-4-yl-2-hydroxy-pentanoic    acid (TFA salt)

MS m/z: [M + H]⁺ Ex. R¹ R³ R⁴ Formula calcd found 25 —OH

H C₂₉H₂₇N₃O₆S 546.16 546.2

-   25.    (2R,4R)-5-Biphenyl-4-yl-2-hydroxy-4-{[2-(2-methoxy-benzoylamino)-thiazole-4-carbonyl]-amino}-pentanoic    acid (TFA salt)

MS m/z: [M + H]⁺ Ex. R¹ R³ R⁴ Formula calcd found 26 —OH 2- absentC₂₆H₂₂ClN₃O₅ 492.12 492.4 chlorophenyl

-   26.    (2R,4R)-5-Biphenyl-4-yl-4-{[3-(2-chlorophenyl)-[1,2,4]oxadiazole-5-carbonyl]-amino}-2-hydroxy-pentanoic    acid

MS m/z: [M + H]⁺ Ex. R¹ R³ R⁴ Formula calcd found 27 —OH ═O H C₂₀H₁₉N₃O₆398.13 398.2

-   27.    (2R,4R)-5-Biphenyl-4-yl-2-hydroxy-4-[(5-oxo-4,5-dihydro-[1,2,4]oxadiazole-3-carbonyl)-amino]-pentanoic    acid

Example 13

These were prepared as the parent compound or as a TFA salt.

MS m/z: [M + H]⁺ Ex. R¹ R³ R⁴ Formula calcd found 1 —OH —COOH HC₂₃H₂₁N₃O₆ 436.14 436.2

-   1.    5-((R)-1-Biphenyl-4-ylmethyl-3-carboxy-3-hydroxypropylcarbamoyl)-pyrazine-2-carboxylic    acid (TFA salt)

MS m/z: [M + H]⁺ Ex. R¹ R³ R⁴ Formula calcd found 2 —OCH₂CH₃ H HC₂₄H₂₅N₃O₄ 420.18 420.4

-   2.    (2R,4R)-5-Biphenyl-4-yl-2-hydroxy-4-[(pyrimidine-5-carbonyl)-amino]-pentanoic    acid ethyl ester (TFA salt)

MS m/z: [M + H]⁺ Ex. R¹ R³ R⁴ Formula calcd found 3 —OH —COOH HC₂₃H₂₁N₃O₆ 436.14 436.2 4 —OCH₂CH₃ —OH H C₂₄H₂₅N₃O₅ 436.18 436.4 5 —OH—OH H C₂₂H₂₁N₃O₅ 408.15 408.2

-   3.    6-((R)-1-Biphenyl-4-ylmethyl-3-carboxy-3-hydroxypropylcarbamoyl)-pyridazine-3-carboxylic    acid (TFA salt)-   4.    (R)-5-Biphenyl-4-yl-2-hydroxy-4-[(6-hydroxypyridazine-3-carbonyl)-amino]-pentanoic    acid ethyl ester-   5.    (R)-5-Biphenyl-4-yl-2-hydroxy-4-[(6-hydroxypyridazine-3-carbonyl)-amino]-pentanoic    acid (TFA salt)

MS m/z: [M + H]⁺ Ex. R¹ R³ R⁴ Formula calcd found 6 —OH H H C₂₂H₂₃N₃O₅410.16 410.0

-   6.    (R)-5-Biphenyl-4-yl-2-hydroxy-4-[(6-oxo-1,4,5,6-tetrahydro-pyridazine-3-carbonyl)-amino]-pentanoic    acid

MS m/z: [M + H]⁺ Ex. R¹ R³ R⁴ Formula calcd found 7 —OH —COOH HC₂₄H₂₂N₂O₆ 435.15 435.2

-   7.    6-((R)-1-Biphenyl-4-ylmethyl-3-carboxy-3-hydroxypropylcarbamoyl)nicotinic    acid

MS m/z: [M + H]⁺ Ex. R¹ R³ R⁴ Formula calcd found 8 —OH —COOH HC₂₄H₂₂N₂O₆ 435.15 435.2

-   8.    5-((R)-1-Biphenyl-4-ylmethyl-3-carboxy-3-hydroxypropylcarbamoyl)-pyridine-2-carboxylic    acid

Example 14

This was prepared as the parent compound.

MS m/z: [M + H]⁺ Ex. R¹ R³ R⁴ Formula calcd found 1 —OH absent HC₁₉H₁₉N₅O₄ 382.14 382.2

-   1.    (R)-5-Biphenyl-4-yl-2-hydroxy-4-[(1H-tetrazole-5-carbonyl)amino]pentanoic    acid

Example 15

These were prepared as TFA salts.

MS m/z: [M + H]⁺ Ex. R¹ R³ R⁴ Formula calcd found  1 —OH H H C₂₁H₂₁N₃O₄380.15 380.0  2 —OH —CH₂COOH H C₂₃H₂₃N₃O₆ 438.16 438.4  3 —OH —CH₂OH HC₂₂H₂₃N₃O₅ 410.16 410.4  4 —OH —CH₂OCH₃ H C₂₃H₂₅N₃O₅ 424.18 424.4  5 —OH—COOH —CH₃ C₂₃H₂₃N₃O₆ 438.16 438.4  6 —OH —COOH 3-SCF₃, 4-Cl-benzylC₃₀H₂₅ClF₃N₃O₆S 648.11 648.0  7 —OH —COOH 3-Cl-benzyl C₂₉H₂₆ClN₃O₆548.15 548.2  8 —OH —COOH 2,6-diF, 4-Cl-benzyl C₂₉H₂₄ClF₂N₃O₆ 584.13584.0  9 —OH —COOH 2-Cl-benzyl C₂₉H₂₆ClN₃O₆ 548.15 548.2 10 —OH —COOH2-Cl, 5-F-benzyl C₂₉H₂₅ClFN₃O₆ 566.14 566.0 11 —OH —COOH 3-Cl,5-F-benzyl C₂₉H₂₅ClFN₃O₆ 566.14 566.0 12 —OH —COOH 3-OCF₃, 4-Cl-benzylC₃₀H₂₅ClF₃N₃O₇ 632.13 632.0 13 —OH —COOH 2-F, 4-Cl-benzyl C₂₉H₂₅ClFN₃O₆566.14 566.2 14 —OH —COOH 3-Cl, 4-F-benzyl C₂₉H₂₅ClFN₃O₆ 566.14 566.2 15—OH —COOH 4-Cl-benzyl C₂₉H₂₆ClN₃O₆ 548.15 548.2 16 —OH —COOH 2,6-diF,3-Cl-benzyl C₂₉H₂₄ClF₂N₃O₆ 584.13 584.0 17 —OH —COOH 3-methoxy-benzylC₃₀H₂₉N₃O₇ 544.20 544.2 18 —OCH₂—CH₃ —C(O)O—CH₂CH₃ H C₂₆H₂₉N₃O₆ 480.21480.2 19 —OH CH₃ H C₂₂H₂₃N₃O₄ 394.17 394.2 20 —OH

H C₂₆H₂₄N₄O₄ 457.18 457.4 21 —OH

H C₂₆H₂₄N₄O₄ 457.18 457.2 22 —OH

H C₂₅H₂₃N₅O₄ 458.18 458.2 23 —OH 1-methyl-1H-pyrazole H C₂₅H₂₅N₅O₄460.19 460.2 24 —OH 2-Cl-phenyl H C₂₇H₂₄ClN₃O₄ 490.15 490.0 25 —OH3-Cl-phenyl H C₂₇H₂₄ClN₃O₄ 490.15 490.4 26 —OH 2,4-diCl-phenyl HC₂₇H₂₃Cl₂N₃O₄ 524.11 524.0 27 —OH 2,5-diCl-phenyl H C₂₇H₂₃Cl₂N₃O₄ 524.11524.0 28 —OH 2-hydroxy-phenyl H C₂₇H₂₅N₃O₅ 472.18 472.6 29 —OCH₂—CH₃2-hydroxy-phenyl H C₂₉H₂₉N₃O₅ 500.21 500.4 30 —OH 2-hydroxy-phenyl—CH₂—CHOH—CH₂OH C₃₀H₃₁N₃O₇ 546.22 546.4 31 —OH 3-NHC(O)—CH₃-phenyl HC₂₉H₂₈N₄O₅ 513.21 513.2 32 —OH

H C₂₉H₂₈N₄O₆ 529.20 530.4 33 —OH phenyl H C₂₇H₂₅N₃O₄ 456.18 456.2 34 —OHphenyl —CH₃ C₂₈H₂₇N₃O₄ 470.20 470.2 35 —OH phenyl —CH_(2—)COOHC₂₉H₂₇N₃O₆ 514.19 514.6 36 —OH phenyl —(CH₂)₂—COOH C₃₀H₂₉N₃O₆ 528.21528.2 37 —OH furan H C₂₅H₂₃N₃O₅ 446.16 446.2 38 —OH napthyl H C₃₁H₂₇N₃O₄506.20 506.2 39 —OH 4-biphenyl H C₃₃H₂₉N₃O₄ 532.22 532.2 40 —OH4-Cl-phenyl H C₂₇H₂₄ClN₃O₄ 490.15 490.2 41

—C(CH₃)₂OH H C₂₉H₃₁N₃O₈ 550.21 550.4

-   1.    (R)-5-Biphenyl-4-yl-2-hydroxy-4-[(1H-pyrazole-3-carbonyl)amino]pentanoic    acid-   2.    (2R,4R)-5-Biphenyl-4-yl-4-[(5-carboxymethyl-1H-pyrazole-3-carbonyl)amino]-2-hydroxy-pentanoic    acid-   3.    (2R,4R)-5-Biphenyl-4-yl-2-hydroxy-4-[(5-hydroxymethyl-1H-pyrazole-3-carbonyl)-amino]-pentanoic    acid-   4.    (2R,4R)-5-Biphenyl-4-yl-2-hydroxy-4-[(5-methoxymethyl-1H-pyrazole-3-carbonyl)-amino]-pentanoic    acid-   5.    5-((1R,3R)-1-Biphenyl-4-ylmethyl-3-carboxy-3-hydroxypropylcarbamoyl)-2-methyl-2H-pyrazole-3-carboxylic    acid-   6.    5-((R)-1-Biphenyl-4-ylmethyl-3-carboxy-3-hydroxypropylcarbamoyl)-2-(4-chloro-3-trifluoromethylsulfanyl-benzyl)-2H-pyrazole-3-carboxylic    acid-   7.    5-((R)-1-Biphenyl-4-ylmethyl-3-carboxy-3-hydroxypropylcarbamoyl)-2-(3-chlorobenzyl)-2H-pyrazole-3-carboxylic    acid-   8.    5-((R)-1-Biphenyl-4-ylmethyl-3-carboxy-3-hydroxy-propylcarbamoyl)-2-(4-chloro-2,6-difluorobenzyl)-2H-pyrazole-3-carboxylic    acid-   9.    5-((R)-1-Biphenyl-4-ylmethyl-3-carboxy-3-hydroxy-propylcarbamoyl)-2-(2-chlorobenzyl)-2H-pyrazole-3-carboxylic    acid-   10.    5-((R)-1-Biphenyl-4-ylmethyl-3-carboxy-3-hydroxy-propylcarbamoyl)-2-(2-chloro-5-fluorobenzyl)-2H-pyrazole-3-carboxylic    acid-   11.    5-((R)-1-Biphenyl-4-ylmethyl-3-carboxy-3-hydroxy-propylcarbamoyl)-2-(3-chloro-5-fluorobenzyl)-2H-pyrazole-3-carboxylic    acid-   12.    5-((R)-1-Biphenyl-4-ylmethyl-3-carboxy-3-hydroxy-propylcarbamoyl)-2-(4-chloro-3-trifluoromethoxybenzyl)-2H-pyrazole-3-carboxylic    acid-   13.    5-((R)-1-Biphenyl-4-ylmethyl-3-carboxy-3-hydroxy-propylcarbamoyl)-2-(4-chloro-2-fluorobenzyl)-2H-pyrazole-3-carboxylic    acid-   14.    5-((R)-1-Biphenyl-4-ylmethyl-3-carboxy-3-hydroxy-propylcarbamoyl)-2-(3-chloro-4-fluorobenzyl)-2H-pyrazole-3-carboxylic    acid-   15.    5-((R)-1-Biphenyl-4-ylmethyl-3-carboxy-3-hydroxy-propylcarbamoyl)-2-(4-chlorobenzyl)-2H-pyrazole-3-carboxylic    acid-   16.    5-((R)-1-Biphenyl-4-ylmethyl-3-carboxy-3-hydroxy-propylcarbamoyl)-2-(3-chloro-2,6-difluorobenzyl)-2H-pyrazole-3-carboxylic    acid-   17.    5-((R)-1-Biphenyl-4-ylmethyl-3-carboxy-3-hydroxy-propylcarbamoyl)-2-(3-methoxy-benzyl)-2H-pyrazole-3-carboxylic    acid-   18.    5-((R)-1-Biphenyl-4-ylmethyl-3-ethoxycarbonyl-3-hydroxy-propylcarbamoyl)-2H-pyrazole-3-carboxylic    acid ethyl ester-   19.    (R)-5-Biphenyl-4-yl-2-hydroxy-4-[(5-methyl-1H-pyrazole-3-carbonyl)amino]pentanoic    acid-   20.    (2R,4R)-5-Biphenyl-4-yl-2-hydroxy-4-[(5-pyridin-4-yl-1H-pyrazole-3-carbonyl)-amino]-pentanoic    acid-   21.    (2R,4R)-5-Biphenyl-4-yl-2-hydroxy-4-[(5-pyridin-3-yl-1H-pyrazole-3-carbonyl)-amino]-pentanoic    acid-   22.    (R)-5-Biphenyl-4-yl-2-hydroxy-4-[(5-pyrazin-2-yl-1H-pyrazole-3-carbonyl)amino]-pentanoic    acid-   23. (R)-5-Biphenyl-4-yl-2-hydroxy-4-[(1′-methyl-2H,    1′H-[3,4′]bipyrazolyl-5-carbonyl)amino]-pentanoic acid-   24.    (R)-5-Biphenyl-4-yl-4-{[5-(2-chlorophenyl)-1H-pyrazole-3-carbonyl]amino}-2-hydroxy-pentanoic    acid-   25.    (2R,4R)-5-Biphenyl-4-yl-4-{[5-(3-chlorophenyl)-1H-pyrazole-3-carbonyl]-amino}-2-hydroxy-pentanoic    acid-   26.    (2R,4R)-5-Biphenyl-4-yl-4-{[5-(2,4-dichlorophenyl)-1H-pyrazole-3-carbonyl]-amino}-2-hydroxy-pentanoic    acid-   27.    (2R,4R)-5-Biphenyl-4-yl-4-{[5-(2,5-dichlorophenyl)-1H-pyrazole-3-carbonyl]-amino}-2-hydroxy-pentanoic    acid-   28.    (2R,4R)-5-Biphenyl-4-yl-2-hydroxy-4-{[5-(2-hydroxy-phenyl)-1H-pyrazole-3-carbonyl]-amino}-pentanoic    acid-   29.    (2R,4R)-5-Biphenyl-4-yl-2-hydroxy-4-{[5-(2-hydroxy-phenyl)-1H-pyrazole-3-carbonyl]-amino}-pentanoic    acid ethyl ester-   30.    (2R,4R)-5-Biphenyl-4-yl-4-{[1-(2,3-dihydroxy-propyl)-5-(2-hydroxy-phenyl)-1H-pyrazole-3-carbonyl]-amino}-2-hydroxy-pentanoic    acid-   31.    (R)-4-{[5-(3-Acetylamino-phenyl)-1H-pyrazole-3-carbonyl]amino}-5-biphenyl-4-yl-2-hydroxypentanoic    acid-   32.    (2R,4R)-5-Biphenyl-4-yl-2-hydroxy-4-{[5-(2-methoxy-benzoylamino)-1H-pyrazole-3-carbonyl]-amino}-pentanoic    acid-   33.    (2R,4R)-5-Biphenyl-4-yl-2-hydroxy-4-[(5-phenyl-1H-pyrazole-3-carbonyl)-amino]-pentanoic    acid-   34.    (R)-5-Biphenyl-4-yl-2-hydroxy-4-[(1-methyl-5-phenyl-1H-pyrazole-3-carbonyl)amino]-pentanoic    acid-   35.    (2R,4R)-5-Biphenyl-4-yl-4-[(1-carboxymethyl-5-phenyl-1H-pyrazole-3-carbonyl)-amino]-2-hydroxy-pentanoic    acid-   36.    (2R,4R)-5-Biphenyl-4-yl-4-{[1-(2-carboxy-ethyl)-5-phenyl-1H-pyrazole-3-carbonyl]-amino}-2-hydroxy-pentanoic    acid-   37.    (R)-5-Biphenyl-4-yl-4-[(5-furan-2-yl-1H-pyrazole-3-carbonyl)amino]-2-hydroxy-pentanoic    acid-   38.    (R)-5-Biphenyl-4-yl-2-hydroxy-4-[(5-naphthalen-2-yl-1H-pyrazole-3-carbonyl)amino]-pentanoic    acid-   39.    (R)-5-Biphenyl-4-yl-4-[(5-biphenyl-4-yl-1H-pyrazole-3-carbonyl)amino]-2-hydroxy-pentanoic    acid-   40.    (R)-5-Biphenyl-4-yl-4-{[5-(4-chlorophenyl)-1H-pyrazole-3-carbonyl]amino}-2-hydroxy-pentanoic    acid-   41.    (2R,4R)-5-Biphenyl-4-yl-2-hydroxy-4-{[5-(1-hydroxy-1-methylethyl)-1H-pyrazole-3-carbonyl]amino}pentanoic    acid 5-methyl-2-oxo-[1,3]dioxol-4-ylmethyl ester

MS m/z: [M + H]⁺ Ex. R¹ R³ R⁴ Formula calcd found 42 —OH

H C₂₆H₂₈N₄O₆ 493.20 493.2 43 —OCH₂—CH₃

H C₂₉H₃₃N₅O₆ 548.24 548.2 44 —OH

H C₂₇H₂₉N₅O₆ 520.21 520.2 45 —OCH₂—CH₃

H C₂₉H₃₃N₅O₆ 548.24 548.2 46 —OH

H C₂₇H₂₉N₅O₆ 520.21 520.2 47 —OCH₂—CH₃

H C₂₉H₃₄N₄O₆ 535.25 535.2 48 —OH

H C₂₇H₃₀N₄O₆ 507.22 507.2 49 —OCH₂—CH₃

H C₂₉H₃₄N₄O₆ 535.25 535.2 50 —OH

H C₂₇H₃₀N₄O₆ 507.22 507.2 51 —OCH₂—CH₃

H C₂₈H₃₂N₄O₆ 521.23 521.4 52 —OCH₂—CH₃ —C(O)NH-cyclopropyl H C₂₇H₃₀N₄O₅491.22 491.2 53 —OH

H C₂₆H₂₈N₄O₆ 493.20 493.2 54 —OCH₂—CH₃ —C(O)NH-cyclopropyl H C₂₇H₃₀N₄O₅491.22 491.2 55 —OH —C(O)NH-cyclopropyl H C₂₅H₂₆N₄O₅ 463.19 463.2 56 —OH—C(O)NH—CH₂COOH H C₂₄H₂₄N₄O₇ 481.16 481.2 57 —OH —C(O)NH-cyclopropyl HC₂₅H₂₆N₄O₅ 463.19 463.2 58 —OCH₂—CH₃ —C(O)NH₂ H C₂₄H₂₆N₄O₅ 451.19 451.259 —OH —C(O)NH₂ H C₂₂H₂₂N₄O₅ 423.16 424.0 60 —OH —C(O)—NHCH₃ HC₂₃H₂₄N₄O₅ 437.17 437.4 61 —OH —C(O)NH—(CH₂)₂CH₃ H C₂₅H₂₈N₄O₅ 465.21465.2 62 —OCH₂—CH₃ —C(O)—N(CH₃)₂ H C₂₆H₃₀N₄O₅ 479.22 479.2 63 —OH—C(O)—N(CH₃)₂ H C₂₄H₂₆N₄O₅ 451.19 451.2 64 —OCH₂—CH₃—C(O)—N(CH₃)—CH₂—CH(CH₃)₂ H C₂₉H₃₆N₄O₅ 521.27 521.2 65 —OH—C(O)—N(CH₃)—CH₂—CH(CH₃)₂ H C₂₇H₃₂N₄O₅ 493.24 493.2 66 —OCH₂—CH₃—C(O)—N(CH₃)—CH₂—CH(CH₃)₂ H C₂₉H₃₆N₄O₅ 521.27 521.2 67 —OH—C(O)—N(CH₃)—CH₂—CH(CH₃)₂ H C₂₇H₃₂N₄O₅ 493.24 493.4 68 —OCH₂—CH₃—C(O)NH—(CH₂)₂-imidazole H C₂₉H₃₂N₆O₅ 545.24 545.2 69 —OH—C(O)NH—(CH₂)₂-imidazole H C₂₇H₂₈N₆O₅ 517.21 517.2 70 —OH—C(O)—NH—(CH₂)₂—OH H C₂₄H₂₆N₄O₆ 467.19 467.2 71 —OH—C(O)NH—(CH₂)₂—N(CH₃)₂ H C₂₆H₃₁N₅O₅ 494.23 494.2 72 —OH cyclopropyl HC₂₄H₂₅N₃O₄ 420.18 420.2 73 —OH —CH(CH₃)₂ H C₂₄H₂₇N₃O₄ 422.20 422.2 74—OH —(CH₂)₂—CH₃ H C₂₄H₂₇N₃O₄ 422.20 422.2 75 —OH —(CH₂)₃—CH₃ HC₂₅H₂₉N₃O₄ 436.22 436.2 76 —OH phenyl H C₂₇H₂₅N₃O₄ 456.18 456.2 77 —OHphenyl —(CH₂)₂ COOH C₃₀H₂₉N₃O₆ 528.21 528.4 78 —OH 2-hydroxy-phenyl—CH₂ CHOH—CH₂OH C₃₀H₃₁N₃O₇ 546.22 546.2 79 —OH 2-methoxy-phenyl HC₂₈H₂₇N₃O₅ 486.20 486.6 80 —OH 2,5-dimethoxy-phenyl H C₂₉H₂₉N₃O₆ 516.21516.2 81 —OH 2-CF₃-phenyl H C₂₈H₂₄F₃N₃O₄ 524.17 524.2 82 —OH 4-F-phenylH C₂₇H₂₄FN₃O₄ 474.18 474.2 83 —OH 4-Cl-phenyl H C₂₇H₂₄ClN₃O₄ 490.15490.4 84 —OH 2-Cl-phenyl H C₂₇H₂₄ClN₃O₄ 490.15 490.4 85 —OCH₂—CH₃2-Cl-phenyl H C₂₉H₂₈ClN₃O₄ 518.18 518.4 86 —OH 2-methoxy, 5-fluorophenylH C₂₈H₂₆FN₃O₅ 504.19 504.2 87 —OCH—(CH₃)₂ 2-methoxy, 5-fluorophenyl HC₃₁H₃₂FN₃O₅ 546.23 546.2 88 —OCH₂—CH₃ 2-methoxy, 5-fluoro-phenyl HC₃₀H₃₀FN₃O₅ 532.22 532.4 89 —OH 2-methyl-thiophene H C₂₆H₂₅N₃O₄S 476.16476.0 90 —OH 2-chloro-thiophene H C₂₅H₂₂ClN₃O₄S 496.10 497.0 91 —OH—NHC(O)—CH₂CH₃ H C₂₄H₂₆N₄O₅ 451.19 451.2 92 —OH —NHC(O)—(CH₂)₃CH₃ HC₂₆H₃₀N₄O₅ 479.22 479.2 93 —OH —NHC(O)—O—CH₂CH₃ H C₂₄H₂₆N₄O₆ 467.19467.2 94 —OH —NHC(O)—CH₂—OCH₃ H C₂₄H₂₆N₄O₆ 467.19 467.2 95 —OH—NHC(O)-2-methoxy-phenyl H C₂₉H₂₈N₄O₆ 529.20 529.2 96 —OH

H C₂₈H₂₅ClN₄O₅ 533.15 533.2 97 —OCH₂—CH₃

H C₃₀H₂₉ClN₄O₅ 561.18 561.2 98 —OCH₂—CH—(CH₃)₂

H C₃₂H₃₃ClN₄O₅ 589.21 589.2 99 —O—CH—(CH₃)₂

H C₃₁H₃₁ClN₄O₅ 575.20 575.2 100  —OH —NHC(O)-2-pyridine H C₂₇H₂₅N₅O₅500.19 500.2 101  —OH —NH₂ H C₂₁H₂₂N₄O₄ 395.16 395.0 102  —OH

H C₂₆H₂₄N₄O₄ 457.18 457.6 103  —OCH₂—CH₃

H C₂₈H₂₈N₄O₄ 485.21 485.6 104  —OCH₂—CH—(CH₃)₂

H C₃₀H₃₂N₄O₄ 513.24 513.6 105 

H C₃₁H₂₈N₄O₇ 569.20 569.4 106  —OH pyrazine H C₂₅H₂₃N₅O₄ 458.18 458.2107  —O—CH—(CH₃)OC(O)O- —C(O)CH₃ H C₃₂H₃₇N₃O₈ 592.26 592.6 cyclo-hexyl108  —NH₂ —C(O)CH₃ H C₂₃H₂₄N₄O₄ 421.18 421.2 109  —OH —CH(OH)—CH₃ HC₂₃H₂₅N₃O₅ 424.18 424.2 110  —OH —CH(OH)—CH₃ H C₂₃H₂₅N₃O₅ 424.18 424.4111  —OH —C(CH₃)═N(OH) H C₂₃H₂₄N₄O₅ 437.17 437.4 112  —OH —(CH₂)₃—CH₃ HC₂₅H₂₉N₃O₄ 436.22 436.4

-   42.    (R)-5-Biphenyl-4-yl-2-hydroxy-4-{[5-(3-hydroxypyrrolidine-1-carbonyl)-2H-pyrazole-3-carbonyl]-amino}-pentanoic    acid-   43.    (2S,4R)-5-Biphenyl-4-yl-4-{[5-(3-carbamoylpyrrolidine-1-carbonyl)-2H-pyrazole-3-carbonyl]-amino}-2-hydroxy-pentanoic    acid ethyl ester-   44.    (2S,4R)-5-Biphenyl-4-yl-4-{[5-(3-carbamoylpyrrolidine-1-carbonyl)-2H-pyrazole-3-carbonyl]-amino}-2-hydroxy-pentanoic    acid-   45.    (2R,4R)-5-Biphenyl-4-yl-4-{[5-(3-carbamoylpyrrolidine-1-carbonyl)-2H-pyrazole-3-carbonyl]-amino}-2-hydroxy-pentanoic    acid ethyl ester-   46.    (2R,4R)-5-Biphenyl-4-yl-4-{[5-(3-carbamoylpyrrolidine-1-carbonyl)-2H-pyrazole-3-carbonyl]-amino}-2-hydroxy-pentanoic    acid-   47.    (2R,4R)-5-Biphenyl-4-yl-2-hydroxy-4-{[5-(4-hydroxypiperidine-1-carbonyl)-2H-pyrazole-3-carbonyl]-amino}-pentanoic    acid ethyl ester-   48.    (2R,4R)-5-Biphenyl-4-yl-2-hydroxy-4-{[5-(4-hydroxypiperidine-1-carbonyl)-2H-pyrazole-3-carbonyl]-amino}-pentanoic    acid-   49.    (2S,4R)-5-Biphenyl-4-yl-2-hydroxy-4-{[5-(4-hydroxypiperidine-1-carbonyl)-2H-pyrazole-3-carbonyl]amino}-pentanoic    acid ethyl ester-   50.    (2S,4R)-5-Biphenyl-4-yl-2-hydroxy-4-{[5-(4-hydroxypiperidine-1-carbonyl)-2H-pyrazole-3-carbonyl]-amino}-pentanoic    acid-   51.    (R)-5-Biphenyl-4-yl-2-hydroxy-4-{[5-(morpholine-4-carbonyl)-2H-pyrazole-3-carbonyl]-amino}-pentanoic    acid ethyl ester-   52.    (2S,4R)-5-Biphenyl-4-yl-4-[(5-cyclopropylcarbamoyl-2H-pyrazole-3-carbonyl)-amino]-2-hydroxypentanoic    acid ethyl ester-   53.    (R)-5-Biphenyl-4-yl-2-hydroxy-4-{[5-(morpholine-4-carbonyl)-2H-pyrazole-3-carbonyl]amino}pentanoic    acid-   54.    (2R,4R)-5-Biphenyl-4-yl-4-[(5-cyclopropylcarbamoyl-2H-pyrazole-3-carbonyl)-amino]-2-hydroxypentanoic    acid ethyl ester-   55.    (2S,4R)-5-Biphenyl-4-yl-4-[(5-cyclopropylcarbamoyl-2H-pyrazole-3-carbonyl)-amino]-2-hydroxypentanoic    acid-   56.    (R)-5-Biphenyl-4-yl-4-{[5-(carboxymethyl-carbamoyl)-2H-pyrazole-3-carbonyl]-amino}-2-hydroxy-pentanoic    acid-   57.    (2R,4R)-5-Biphenyl-4-yl-4-[(5-cyclopropylcarbamoyl-2H-pyrazole-3-carbonyl)-amino]-2-hydroxypentanoic    acid-   58.    (R)-5-Biphenyl-4-yl-4-[(5-carbamoyl-2H-pyrazole-3-carbonyl)-amino]-2-hydroxy-pentanoic    acid ethyl ester-   59.    (R)-5-Biphenyl-4-yl-4-[(5-carbamoyl-2H-pyrazole-3-carbonyl)-amino]-2-hydroxy-pentanoic    acid-   60.    (2R,4R)-5-Biphenyl-4-yl-2-hydroxy-4-[(5-methylcarbamoyl-2H-pyrazole-3-carbonyl)-amino]pentanoic    acid-   61.    (R)-5-Biphenyl-4-yl-2-hydroxy-4-[(5-propylcarbamoyl-2H-pyrazole-3-carbonyl)-amino]pentanoic    acid-   62.    (2R,4R)-5-Biphenyl-4-yl-4-[(5-dimethylcarbamoyl-2H-pyrazole-3-carbonyl)-amino]-2-hydroxy-pentanoic    acid ethyl ester-   63.    (2R,4R)-5-Biphenyl-4-yl-4-[(5-dimethylcarbamoyl-2H-pyrazole-3-carbonyl)-amino]-2-hydroxy-pentanoic    acid-   64.    (2S,4R)-5-Biphenyl-4-yl-2-hydroxy-4-{[5-(isobutyl-methyl-carbamoyl)-2H-pyrazole-3-carbonyl]-amino}-pentanoic    acid ethyl ester-   65.    (2S,4R)-5-Biphenyl-4-yl-2-hydroxy-4-{[5-(isobutylmethyl-carbamoyl)-2H-pyrazole-3-carbonyl]amino}-pentanoic    acid-   66.    (2R,4R)-5-Biphenyl-4-yl-2-hydroxy-4-{[5-(isobutylmethyl-carbamoyl)-2H-pyrazole-3-carbonyl]amino}-pentanoic    acid ethyl ester-   67.    (2R,4R)-5-Biphenyl-4-yl-2-hydroxy-4-{[5-(isobutylmethyl-carbamoyl)-2H-pyrazole-3-carbonyl]amino}-pentanoic    acid-   68.    (2R,4R)-5-Biphenyl-4-yl-2-hydroxy-4-({5-[2-(1H-imidazol-4-yl)-ethylcarbamoyl]-2H-pyrazole-3-carbonyl}amino)pentanoic    acid ethyl ester-   69.    (2R,4R)-5-Biphenyl-4-yl-2-hydroxy-4-({5-[2-(3H-imidazol-4-yl)-ethylcarbamoyl]-2H-pyrazole-3-carbonyl}amino)pentanoic    acid-   70.    (R)-5-Biphenyl-4-yl-2-hydroxy-4-{[5-(2-hydroxy-ethylcarbamoyl)-2H-pyrazole-3-carbonyl]-amino}-pentanoic    acid-   71.    (R)-5-Biphenyl-4-yl-4-{[5-(2-dimethylamino-ethylcarbamoyl)-2H-pyrazole-3-carbonyl]-amino}-2-hydroxy-pentanoic    acid-   72.    (R)-5-Biphenyl-4-yl-4-[(5-cyclopropyl-2H-pyrazole-3-carbonyl)-amino]-2-hydroxy-pentanoic    acid-   73.    (R)-5-Biphenyl-4-yl-2-hydroxy-4-[(5-isopropyl-2H-pyrazole-3-carbonyl)amino]-pentanoic    acid-   74.    (R)-5-Biphenyl-4-yl-2-hydroxy-4-[(5-propyl-2H-pyrazole-3-carbonyl)amino]-pentanoic    acid-   75.    (R)-5-Biphenyl-4-yl-4-[(5-butyl-2H-pyrazole-3-carbonyl)-amino]-2-hydroxy-pentanoic    acid-   76.    (R)-5-Biphenyl-4-yl-2-hydroxy-4-[(5-phenyl-2H-pyrazole-3-carbonyl)-amino]-pentanoic    acid-   77.    (2R,4R)-5-Biphenyl-4-yl-4-{[2-(2-carboxy-ethyl)-5-phenyl-2H-pyrazole-3-carbonyl]-amino}-2-hydroxy-pentanoic    acid-   78.    (2R,4R)-5-Biphenyl-4-yl-4-{[2-(2,3-dihydroxy-propyl)-5-(2-hydroxy-phenyl)-2H-pyrazole-3-carbonyl]-amino}-2-hydroxy-pentanoic    acid-   79.    (2R,4R)-5-Biphenyl-4-yl-2-hydroxy-4-{[5-(2-methoxy-phenyl)-2H-pyrazole-3-carbonyl]-amino}-pentanoic    acid-   80.    (2R,4R)-5-Biphenyl-4-yl-4-{[5-(2,5-dimethoxy-phenyl)-2H-pyrazole-3-carbonyl]-amino}-2-hydroxy-pentanoic    acid-   81.    (R)-5-Biphenyl-4-yl-2-hydroxy-4-{[5-(2-trifluoromethyl-phenyl)-2H-pyrazole-3-carbonyl]-amino}-pentanoic    acid-   82.    (R)-5-Biphenyl-4-yl-4-{[5-(4-fluorophenyl)-2H-pyrazole-3-carbonyl]amino}-2-hydroxy-pentanoic    acid-   83.    (2R,4R)-5-Biphenyl-4-yl-4-{[5-(4-chlorophenyl)-2H-pyrazole-3-carbonyl]--   84.    (2R,4R)-5-Biphenyl-4-yl-4-{[5-(2-chlorophenyl)-2H-pyrazole-3-carbonyl]amino}-2-hydroxy-pentanoic    acid-   85.    (2R,4R)-5-Biphenyl-4-yl-4-{[5-(2-chlorophenyl)-2H-pyrazole-3-carbonyl]-amino}-2-hydroxy-pentanoic    acid ethyl ester-   86.    (2R,4R)-5-Biphenyl-4-yl-4-{[5-(5-fluoro-2-methoxy-phenyl)-2H-pyrazole-3-carbonyl]-amino}-2-hydroxy-pentanoic    acid-   87.    (2R,4R)-5-Biphenyl-4-yl-4-{[5-(5-fluoro-2-methoxy-phenyl)-2H-pyrazole-3-carbonyl]-amino}-2-hydroxy-pentanoic    acid isopropyl ester (HCL salt)-   88.    (2R,4R)-5-Biphenyl-4-yl-4-{[5-(5-fluoro-2-methoxy-phenyl)-2H-pyrazole-3-carbonyl]-amino}-2-hydroxy-pentanoic    acid ethyl ester-   89.    (2R,4R)-5-Biphenyl-4-yl-2-hydroxy-4-{[5-(5-methylthiophen-2-yl)-2H-pyrazole-3-carbonyl]-amino}-pentanoic    acid-   90.    (2R,4R)-5-Biphenyl-4-yl-4-{[5-(5-chlorothiophen-2-yl)-2H-pyrazole-3-carbonyl]-amino}-2-hydroxy-pentanoic    acid-   91.    (R)-5-Biphenyl-4-yl-2-hydroxy-4-[(5-propionylamino-2H-pyrazole-3-carbonyl)-amino]-pentanoic    acid-   92.    (R)-5-Biphenyl-4-yl-2-hydroxy-4-[(5-pentanoylamino-2H-pyrazole-3-carbonyl)-amino]-pentanoic    acid-   93.    (R)-5-Biphenyl-4-yl-4-[(5-ethoxycarbonylamino-2H-pyrazole-3-carbonyl)-amino]-2-hydroxy-pentanoic    acid-   94.    (R)-5-Biphenyl-4-yl-2-hydroxy-4-{[5-(2-methoxy-acetylamino)-2H-pyrazole-3-carbonyl]-amino}-pentanoic    acid-   95.    (R)-5-Biphenyl-4-yl-2-hydroxy-4-{[5-(2-methoxy-benzoylamino)-2H-pyrazole-3-carbonyl]-amino}-pentanoic    acid-   96.    (2R,4R)-5-Biphenyl-4-yl-4-{[5-(2-chlorobenzoylamino)-2H-pyrazole-3-carbonyl]-amino}-2-hydroxy-pentanoic    acid-   97.    (2R,4R)-5-Biphenyl-4-yl-4-{[5-(2-chlorobenzoylamino)-2H-pyrazole-3-carbonyl]-amino}-2-hydroxy-pentanoic    acid ethyl ester-   98.    (2R,4R)-5-Biphenyl-4-yl-4-{[5-(2-chlorobenzoylamino)-2H-pyrazole-3-carbonyl]-amino}-2-hydroxy-pentanoic    acid isobutyl ester-   99.    (2R,4R)-5-Biphenyl-4-yl-4-{[5-(2-chlorobenzoylamino)-2H-pyrazole-3-carbonyl]-amino}-2-hydroxy-pentanoic    acid isopropyl ester-   100.    (R)-5-Biphenyl-4-yl-2-hydroxy-4-({5-[(pyridine-2-carbonyl)-amino]-2H-pyrazole-3-carbonyl}-amino)-pentanoic    acid-   101.    (R)-4-[(5-Amino-2H-pyrazole-3-carbonyl)-amino]-5-biphenyl-4-yl-2-hydroxy-pentanoic    acid-   102.    (2R,4R)-5-Biphenyl-4-yl-2-hydroxy-4-[(5-pyridin-2-yl-2H-pyrazole-3-carbonyl)-amino]-pentanoic    acid-   103.    (2R,4R)-5-Biphenyl-4-yl-2-hydroxy-4-[(5-pyridin-2-yl-2H-pyrazole-3-carbonyl)-amino]-pentanoic    acid ethyl ester-   104.    (2R,4R)-5-Biphenyl-4-yl-2-hydroxy-4-[(5-pyridin-2-yl-2H-pyrazole-3-carbonyl)-amino]-pentanoic    acid isobutyl ester-   105.    (2R,4R)-5-Biphenyl-4-yl-2-hydroxy-4-[(5-pyridin-2-yl-2H-pyrazole-3-carbonyl)-amino]-pentanoic    acid 5-methyl-2-oxo-[1,3]dioxol-4-ylmethyl ester-   106.    (2R,4R)-5-Biphenyl-4-yl-2-hydroxy-4-[(5-pyrazin-2-yl-2H-pyrazole-3-carbonyl)-amino]pentanoic    acid-   107.    (2R,4R)-4-[(5-Acetyl-2H-pyrazole-3-carbonyl)amino]-5-biphenyl-4-yl-2-hydroxy-pentanoic    acid 1-cyclohexyloxycarbonyloxyethyl ester-   108. 5-Acetyl-2H-pyrazole-3-carboxylic acid    ((1R,3R)-1-biphenyl-4-ylmethyl-3-carbamoyl-3-hydroxypropyl)amide-   109.    (2R,4R)-5-Biphenyl-4-yl-2-hydroxy-4-{[5-((S)-1-hydroxyethyl)-2H-pyrazole-3-carbonyl]amino}pentanoic    acid-   110.    (2R,4R)-5-Biphenyl-4-yl-2-hydroxy-4-{[5-((R)-1-hydroxyethyl)-2H-pyrazole-3-carbonyl]amino}pentanoic    acid-   111.    (2R,4R)-5-Biphenyl-4-yl-2-hydroxy-4-[(5-{1-[(E)-hydroxyimino]-ethyl}-2H-pyrazole-3-carbonyl)-amino]-pentanoic    acid-   112.    (2R,4R)-5-Biphenyl-4-yl-4-[(5-butyl-2H-pyrazole-3-carbonyl)-amino]-2-hydroxy-pentanoic    acid

MS m/z: [M + H]⁺ Ex. R¹ R³ R⁴ Formula calcd found 113 —OH H H C₂₁H₂₁N₃O₄380.15 380.2

-   113.    (R)-5-Biphenyl-4-yl-2-hydroxy-4-[(1H-pyrazole-4-carbonyl)amino]pentanoic    acid

Example 16

Following the procedures described in the examples herein, andsubstituting the appropriate starting materials and reagents, compoundshaving the following formula were prepared as TFA salts.

MS m/z: [M + H]⁺ Ex. —XR³R⁴ Formula calcd found 1

C₂₉H₂₇N₃O₅ 498.20 498.8 2

C₂₉H₂₇N₃O₅ 498.20 498.6 3

C₃₀H₂₉N₃O₅ 512.21 512.6 4

C₃₀H₂₉N₃O₆ 528.21 528.4 5

C₃₀H₂₉N₃O₆ 528.21 528.4 6

C₂₈H₂₅N₃O₅ 484.18 484.6

-   1.    (2R,4R)-5-Biphenyl-4-yl-4-[(4,5-dihydro-6-oxa-3,3a-diaza-benzo[e]azulene-2-carbonyl)-amino]-2-hydroxy-pentanoic    acid-   2.    (2R,4R)-5-Biphenyl-4-yl-2-hydroxy-4-[(8-oxa-11,14-diaza-tricyclo[9.2.1.02,7]tetradeca-1(14),2,4,6,12-pentaene-12-carbonyl)-amino]-pentanoic    acid-   3.    (2R,4R)-5-Biphenyl-4-yl-2-hydroxy-4-[(10-oxa-5,6-diaza-tricyclo[9.4.0.02,6]pentadeca-1(15),2,4,11,13-pentaene-4-carbonyl)-amino]-pentanoic    acid-   4.    (2R,4R)-5-Biphenyl-4-yl-2-hydroxy-4-[((S)-8-hydroxy-10-oxa-5,6-diaza-tricyclo[9.4.0.02,6]pentadeca-1(15),2,4,11,13-pentaene-4-carbonyl)-amino]-pentanoic    acid-   5.    (2R,4R)-5-Biphenyl-4-yl-2-hydroxy-4-[((R)-8-hydroxy-10-oxa-5,6-diaza-tricyclo[9.4.0.02,6]pentadeca-1(15),2,4,11,13-pentaene-4-carbonyl)-amino]-pentanoic    acid-   6.    (2R,4R)-5-Biphenyl-4-yl-2-hydroxy-4-[(5-oxa-3,3a-diaza-cyclopenta[a]naphthalene-2-carbonyl)-amino]-pentanoic    acid

Preparation 9 (S)-2-(4-Bromobenzyl)-5-oxopyrrolidine-1-carboxylic Acidt-Butyl Ester

To a solution of (R)-2-amino-3-(4-bromophenyl)propionic acid (50 g, 0.2mol) in MeCN (700 mL) was added a solution of NaOH (16.4 g, 0.4 mol) inwater (700 mL) at −5° C. After stirring for 10 minutes, a solution of(Boc)₂O (44.7 g, 0.2 mol) in MeCN (100 mL) was added. The mixture waswarmed to room temperature and stirred overnight. After the evaporationof the MeCN, the residue was diluted with DCM (800 mL) and acidifiedwith 1 M HCl to pH=2 at −5° C. The aqueous was extracted with DCM (3×200mL). The combined organic layers were washed with saturated aqueous NaCl(500 mL), dried over Na₂SO₄ and concentrated to yield compound 1 (66.5g) as a white solid. LC-MS: 366 (M+Na), 709 (2M⁺Na).

To a solution of compound 1 (66.5 g, 193 μmol), Meldrum's acid (33.4 g,232 mmol) and DMAP (37.7 g, 309 mmol) in anhydrous DCM (600 mL), wasadded dropwise a solution of DCC (47.9 g, 232 mmol) in anhydrous DCM(200 mL) over 1 hour at −5° C. under nitrogen. The mixture was stirredat −5° C. for 8 hours, then refrigerated overnight. Crystals ofdicyclohexylurea were observed. The mixture was filtered, washed with 5%KHSO₄ (5×200 mL), saturated aqueous NaCl (200 mL) and dried overanhydrous MgSO₄ under refrigeration overnight. The solution was thenevaporated to yield crude compound 2 (91 g) as a light yellow solid.LC-MS: 492 (M+Na), 961(2M⁺Na).

To a solution of crude compound 2 (91 g, 193 mmol) in anhydrous DCM (1L) was added AcOH (127.5 g, 2.1 mol) at −5° C. under nitrogen. Themixture was stirred at −5° C. for 30 minutes, then NaBH₄ (18.3 g, 483mmol) was added in small portions over 1 hour. After stirring foranother 1 hour at −5° C., saturated aqueous NaCl (500 mL) was added. Theorganic layer was washed with saturated aqueous NaCl (2×300 mL) andwater (2×300 mL), dried over MgSO₄, filtered, and concentrated to yieldthe crude product, which was further purified by washing with Et₂O toyield compound 3 (68 g) as a light yellow solid. LC-MS: 478 (M+Na), 933(2M⁺Na).

A solution of compound 3 (68 g, 149 mmol) in anhydrous toluene (500 mL)was refluxed under nitrogen for 3 hours. After evaporation of thesolvent, the residue was purified by chromatography (hexanes:EtOAc=10:1)to yield the title compound (38 g) as a light yellow oil. LC-MS: 376(M+Na), 729 (2M⁺Na).

Preparation 10 (2R,4R)-4-Amino-5-(4-bromophenyl)-2-hydroxypentanoic AcidEthyl Ester

To a solution of (S)-2-(4-bromobenzyl)-5-oxopyrrolidine-1-carboxylicacid t-butyl ester (38 g, 107 mmol) in anhydrous DCM (250 mL) was addedTFA (20 mL, 0.27 mol) at −5° C. under nitrogen. The mixture was warmedto room temperature and stirred overnight. After evaporation of thesolvent, the residue was diluted with EtOAc (300 mL) and washed withsaturated aqueous NaHCO₃ (3×200 mL), water (200 mL), saturated aqueousNaCl (250 mL), dried over Na₂SO₄ and concentrated to yield crudecompound 1 (24 g) as a light yellow solid. LC-MS: 254 (M+H).

To a solution of NaH (8.6 g, 250 mmol) in anhydrous THF (200 mL) wasadded dropwise a solution of compound 1 (24 g, 94 mmol) in anhydrous THF(200 mL) over 30 minutes at 0° C. under nitrogen. The mixture was warmedto room temperature and stirred for 2 hours. After cooling to 0° C.,pivaloyl chloride (18 g, 150 mmol) was added dropwise over 30 minutes.The mixture was warmed to room temperature and stirred overnight. Thereaction was quenched with saturated aqueous NH₄Cl (300 mL) andextracted with EtOAc (3×200 mL). The combined organic layers were washedwith saturated aqueous NaCl (300 mL), dried over MgSO₄, filtered andconcentrated to yield the crude product, which was further purified bychromatography (hexanes:EtOAc=25:1) to yield compound 2 (18 g) as alight yellow solid. LC-MS: 360 (M+Na).

To a solution of compound 2 (18 g, 53 mmol) in anhydrous THF (250 mL)was added dropwise HMDSNa (47.7 mL, 96 mmol) over 30 minutes at −78° C.under nitrogen. After stirring at −78° C. for 90 minutes, a solution of(+)-(8,8-dichlorocamphorylsulfonyl)oxaziridine (31.6 g, 106 mmol) wasadded dropwise over 30 minutes. After stirring at −78° C. for 2 hours,the reaction was quenched with saturated aqueous NH₄Cl (400 mL) andextracted with EtOAc (3×300 mL). The combined organic layers were washedwith saturated aqueous NaCl (300 mL), dried over MgSO₄, filtered, andconcentrated to give the crude product which was further purified bychromatography (hexanes:EtOAc=15:1) to yield compound 3 (8.9 g) as alight yellow solid. LC-MS: 376 (M+Na).

A solution of compound 3 (8.9 g, 25 mmol) in concentrated HCl (81 mL, 81mmol) was heated at 100° C. for 16 hours. The mixture was thenconcentrated to yield the crude product which was further purified bywashing with Et₂O to yield compound 4 (7 g) as a light yellow solid HClsalt. LC-MS: 323 (M+H).

A solution of compound 4 (7 g, 22 mmol) in EtOH (10 mL) was combinedwith 8M HCl in EtOH (120 mL, 960 mmol) at room temperature. The mixturewas heated at 50° C. for 16 hours, then concentrated. The crude productwas further purified by washing with Et₂O to yield the title compound (6g) as a light yellow solid HCl salt. LC-MS: 352 (M+H).

Preparation 11 1-Hydroxy-1H-1,2,3-triazole-4-carboxylic Acid

1-Hydroxy-1H-[1,2,3]triazole-4-carboxylic acid ethyl ester (2.0 g, 13mmol) and EtOH (25 mL) were combined with a pre-dissolved solution oflithium hydroxide monohydrate (1.6 g, 38.2 mmol) and water (10 mL), andstirred at room temperature for 4 hours. The mixture was partiallyconcentrated and acidified with HCl to cause precipitation. The solidwas filtered and dried under vacuum to yield the title compound (1.3 g).

Preparation 12(2R,4R)-5-(4-Bromo-phenyl)-2-hydroxy-4-[(1-hydroxy-1H-1,2,3-triazole-4-carbonyl)-amino]-pentanoicAcid Ethyl Ester

1-Hydroxy-1H-1,2,3-triazole-4-carboxylic acid (163 mg, 1.3 mmol),), HCTU(523 mg, 1.3 mmol), and DMF were combined and stirred for 5 minutes atroom temperature. DIPEA (661 μL, 3.8 mmol) and(2R,4R)-4-amino-5-(4-bromophenyl)-2-hydroxypentanoic acid ethyl ester (4mg, 1.3 mmol) were added and the resulting mixture was stirred for 10minutes. The reaction mixture was evaporated under reduced pressure andpurified (C18 column; 20-70% MeCN in water with 0.05% TFA) to yield thetitle compound (330 mg).

Example 17 A.(2R,4R)-5-(3′-Chlorobiphenyl-4-yl)-2-hydroxy-4-[(1-hydroxy-1H-[1,2,3]triazole-4-carbonyl)-amino]pentanoicAcid

1-Hydroxy-1H-1,2,3-triazole-4-carboxylic acid (17.6 mg, 136 μmol) andHCTU (56.4 mg, 136 μmol) were combined in DMF and stirred for 5 minutesat room temperature. DIPEA (71.2 μl, 409 μmol) and(2R,4R)-4-amino-5-(4-bromophenyl)-2-hydroxypentanoic acid ethyl ester(43 mg, 140 μmol) were added and the resulting mixture was stirred for10 minutes. The reaction mixture was evaporated under reduced pressureand purified (C18 reverse phase column). The purified material wascombined with 3-chlorophenylboronic acid, pinacol ester (48.1 mg, 202μmol), K₂CO₃ (41.8 mg, 302 μmol), EtOH (1 ml) and water (0.3 ml). Oxygenwas removed (high vacuum) and SilicaCat®Pd(0) (0.09 mmol/g loading; 112mg, 10.1 μmol) was quickly added under nitrogen. The mixture wasmicrowaved at 100° C. for 20 minutes, then concentrated. The materialwas redissolved in AcOH and purified by preparative HPLC to yield thetitle compound (12 mg; purity 95%). MS m/z [M+H]⁺ calc'd forC₂₀H₁₉ClN₄O₅, 431.10; found 431.4.

B.(2R,4R)-5-(3′-Chlorobiphenyl-4-yl)-2-hydroxy-4-[(1-hydroxy-H-[1,2,3]triazole-4-carbonyl)-amino]pentanoicAcid Ethyl Ester

(2R,4R)-5-(4-Bromo-phenyl)-2-hydroxy-4-[(1-hydroxy-1H-1,2,3-triazole-4-carbonyl)-amino]-pentanoicacid ethyl ester (120 mg, 281 μmol) and 3-chlorophenylboronic acid,pinacol ester (120 mg, 506 μmol) were combined with K₂CO₃ (116 mg, 842μmol), EtOH (3 mL), and water (0.8 mL). SilicaCat®DPP-Pd (280 μmol/gloading; 1 mg, 28 μmol) was then added and the mixture was heated at 90°C. and the reaction monitored by LC/MS. The reaction was stopped after 2hours, and the mixture was filtered, concentrated and purified (C18reverse phase column; 30-70% MeCN in water with 0.05% TFA). EtOH (5.0mL, 86 mmol) and 4 M HCl in dioxane (1.5 mL, 6.0 mmol) was added and theresulting mixture was stirred at room temperature for 40 minutes, thenconcentrated and purified (C18 reverse phase column; 30-90% MeCN inwater with 0.05% TFA) to yield the title compound (20 mg; purity 95%).MS m/z [M+H]⁺ calc'd for C₂₂H₂₃ClN₄O₅, 459.14; found 459.4.

Example 18

Following the procedures described in the examples herein, andsubstituting the appropriate starting materials and reagents, compoundshaving the following formula were prepared as the parent compound or asa TFA salt.

MS m/z: [M + H]⁺ Ex. R¹ R³ R⁴ Formula calcd found 1 —OCH₂CH₃ H HC₂₂H₂₃ClN₄O₄ 443.14 443.4

-   1.    (2R,4R)-5-(3′-Chlorobiphenyl-4-yl)-2-hydroxy-4-[(3H-[1,2,3]triazole-4-carbonyl)-amino]-pentanoic    acid ethyl ester (TFA salt)

MS m/z: [M + H]⁺ Ex. R¹ R³ R⁴ Formula calcd found 2 —OH H H C₂₀H₁₉ClN₄O₄415.11 415.4

-   2.    (2R,4R)-5-(3′-Chlorobiphenyl-4-yl)-2-hydroxy-4-[(1H-[1,2,3]triazole-4-carbonyl)-amino]-pentanoic    acid (TFA salt)

MS m/z: [M + H]⁺ Ex. R¹ R³ R⁴ Formula calcd found 3 —OH H —OHC₂₄H₂₁ClN₄O₅ 481.12 481.2 4 —OCH₂CH₃ H —OH C₂₆H₂₅ClN₄O₅ 509.15 509.2

-   3.    (2R,4R)-5-(3′-Chlorobiphenyl-4-yl)-2-hydroxy-4-[(3-hydroxy-3H-benzotriazole-5-carbonyl)-amino]-pentanoic    acid-   4.    (2R,4R)-5-(3′-Chlorobiphenyl-4-yl)-2-hydroxy-4-[(3-hydroxy-3H-benzotriazole-5-carbonyl)-amino]-pentanoic    acid ethyl ester

MS m/z: [M + H]⁺ Ex. R¹ R³ R⁴ Formula calcd found 5 —OCH₂CH(CH₃)₂ H —OHC₂₈H₂₉ClN₄O₅ 537.18 537.2 6 —OCH(CH₃)₂ H —OH C₂₇H₂₇ClN₄O₅ 523.17 523.2

-   5.    (2R,4R)-5-(3′-Chlorobiphenyl-4-yl)-2-hydroxy-4-[(3-hydroxy-3H-benzotriazole-5-carbonyl)-amino]-pentanoic    acid isobutyl ester-   6.    (2R,4R)-5-(3′-Chlorobiphenyl-4-yl)-2-hydroxy-4-[(3-hydroxy-3H-benzotriazole-5-carbonyl)-amino]-pentanoic    acid isopropyl ester

MS m/z: [M + H]⁺ Ex. R¹ R³ R⁴ Formula calcd found  7 —OH —C(O)CH₃ HC₂₃H₂₁ClN₂O₆ 457.11 457.2  8 —OH —OCH₃ H C₂₂H₂₁ClN₂O₆ 445.11 445.2  9—OH Cl H C₂₁H₁₈Cl₂N₂O₅ 449.06 450.3 10 —OH —CH(CH₃)₂ H C₂₄H₂₅ClN₂O₅457.15 457.4 11 —OH —(CH₂)₂CH₃ H C₂₄H₂₅ClN₂O₅ 457.15 457.4 12 —OH—CH₂—CH(CH₃)₂ H C₂₅H₂₇ClN₂O₅ 471.16 471.4 13 —OH —C(OH)(CH₃)₂ HC₂₄H₂₅ClN₂O₆ 473.14 472.8 14 —OH —C(CH₃)₃ H C₂₅H₂₇ClN₂O₅ 471.16 470.8

-   7.    (2R,4R)-4-[(3-Acetyl-isoxazole-5-carbonyl)-amino]-5-(3′-chlorobiphenyl-4-yl)-2-hydroxy-pentanoic    acid-   8.    (2R,4R)-5-(3′-Chlorobiphenyl-4-yl)-2-hydroxy-4-[(3-methoxy-isoxazole-5-carbonyl)-amino]-pentanoic    acid-   9.    (2R,4R)-5-(3′-Chloro-biphenyl-4-yl)-4-[(3-chloro-isoxazole-5-carbonyl)-amino]-2-hydroxy-pentanoic    acid-   10.    (2R,4R)-5-(3′-Chloro-biphenyl-4-yl)-2-hydroxy-4-[(3-isopropyl-isoxazole-5-carbonyl)-amino]-pentanoic    acid-   11.    (2R,4R)-5-(3′-Chloro-biphenyl-4-yl)-2-hydroxy-4-[(3-propyl-isoxazole-5-carbonyl)-amino]-pentanoic    acid-   12.    (2R,4R)-5-(3′-Chloro-biphenyl-4-yl)-2-hydroxy-4-[(3-isobutyl-isoxazole-5-carbonyl)-amino]-pentanoic    acid-   13.    (2R,4R)-5-(3′-Chloro-biphenyl-4-yl)-2-hydroxy-4-{[3-(1-hydroxy-1-methyl-ethyl)-isoxazole-5-carbonyl]-amino}-pentanoic    acid-   14.    (2R,4R)-4-[(3-tert-Butyl-isoxazole-5-carbonyl)-amino]-5-(3′-chloro-biphenyl-4-yl)-2-hydroxy-pentanoic    acid

MS m/z: [M + H]⁺ Ex. R¹ R³ R⁴ Formula calcd found 15 —OH 2-chlorophenylH C₂₇H₂₂Cl₂N₂O₅ 525.09 525.4 16 —OH 2-hydroxyphenyl H C₂₇H₂₃ClN₂O₆507.12 507.2

-   15.    (2R,4R)-5-(3′-Chlorobiphenyl-4-yl)-4-{[5-(2-chlorophenyl)-isoxazole-3-carbonyl]-amino}-2-hydroxy-pentanoic    acid-   16.    (2R,4R)-5-(3′-Chlorobiphenyl-4-yl)-2-hydroxy-4-{[5-(2-hydroxyphenyl)-isoxazole-3-carbonyl]-amino}-pentanoic    acid

MS m/z: [M + H]⁺ Ex. R¹ R³ R⁴ Formula calcd found 17 —OH2-hydroxy-phenyl H C₂₇H₂₄ClN₃O₅ 506.14 506.0 18 —OCH₂CH₃2-hydroxy-phenyl H C₂₉H₂₈ClN₃O₅ 534.17 534.2 19 —OH

H C₂₅H₂₂ClN₅O₄ 492.14 492.2 20 —OCH₂CH₃

H C₂₇H₂₆ClN₅O₄ 520.17 520.2 21 —OCH₂—CH(CH₃)

H C₂₉H₃₀ClN₅O₄ 548.20 548.2 22

H C₃₀H₂₆ClN₅O₇ 604.15 604.1 23 —OH

H C₂₆H₂₃ClN₄O₄ 491.14 491.2 24 —OCH₂CH₃

H C₂₈H₂₇ClN₄O₄ 519.17 519.2 25 —OCH₂—CH(CH₃)

H C₃₀H₃₁ClN₄O₄ 547.20 547.1 26 —OCH(CH₃)

H C₂₉H₂₉ClN₄O₄ 533.19 533.2 27 —OH

H C₂₈H₂₄Cl₂N₄O₅ 567.11 567.1 28 —OCH₂CH₃

H C₃₀H₂₈Cl₂N₄O₅ 595.14 595.1 29 —OCH₂—CH(CH₃)

H C₃₂H₃₂Cl₂N₄O₅ 623.18 623.2 30 —OCH(CH₃)

H C₃₁H₃₀Cl₂N₄O₅ 609.16 609.2 31 —OH

H C₂₉H₂₇ClN₄O₆ 563.16 563.2 32 —OH —CH(OH)—CH₃ H C₂₃H₂₄ClN₃O₅ 458.14458.4 33 —OCH₂CH₃

C₂₈H₂₇ClN₄O₄ 519.17 519.4

-   17.    (2R,4R)-5-(3′-Chlorobiphenyl-4-yl)-2-hydroxy-4-{[5-(2-hydroxy-phenyl)-2H-pyrazole-3-carbonyl]-amino}-pentanoic    acid (TFA salt)-   18.    (2R,4R)-5-(3′-Chlorobiphenyl-4-yl)-2-hydroxy-4-{[5-(2-hydroxy-phenyl)-2H-pyrazole-3-carbonyl]-amino}-pentanoic    acid ethyl ester (TFA salt)-   19.    (2R,4R)-5-(3′-Chlorobiphenyl-4-yl)-2-hydroxy-4-[(5-pyrazin-2-yl-2H-pyrazole-3-carbonyl)-amino]-pentanoic    acid (TFA salt)-   20.    (2R,4R)-5-(3′-Chloro-biphenyl-4-yl)-2-hydroxy-4-[(5-pyrazin-2-yl-2H-pyrazole-3-carbonyl)-amino]-pentanoic    acid ethyl ester-   21.    (2R,4R)-5-(3′-Chloro-biphenyl-4-yl)-2-hydroxy-4-[(5-pyrazin-2-yl-2H-pyrazole-3-carbonyl)-amino]-pentanoic    acid isobutyl ester-   22.    (2S,4S)-5-(3′-Chloro-biphenyl-4-yl)-2-hydroxy-4-[(5-pyrazin-2-yl-2H-pyrazole-3-carbonyl)-amino]-pentanoic    acid 5-methyl-2-oxo-[1,3]dioxol-4-ylmethyl ester (TFA salt)-   23.    (2R,4R)-5-(3′-Chlorobiphenyl-4-yl)-2-hydroxy-4-[(5-pyridin-2-yl-2H-pyrazole-3-carbonyl)-amino]-pentanoic    acid (TFA salt)-   24.    (2R,4R)-5-(3′-Chloro-biphenyl-4-yl)-2-hydroxy-4-[(5-pyridin-2-yl-2H-pyrazole-3-carbonyl)-amino]-pentanoic    acid ethyl ester-   25.    (2R,4R)-5-(3′-Chloro-biphenyl-4-yl)-2-hydroxy-4-[(5-pyridin-2-yl-2H-pyrazole-3-carbonyl)-amino]-pentanoic    acid isobutyl ester-   26.    (2R,4R)-5-(3′-Chloro-biphenyl-4-yl)-2-hydroxy-4-[(5-pyridin-2-yl-2H-pyrazole-3-carbonyl)-amino]-pentanoic    acid isopropyl ester-   27.    (2R,4R)-4-{[5-(2-Chlorobenzoylamino)-2H-pyrazole-3-carbonyl]-amino}-5-(3′-chlorobiphenyl-4-yl)-2-hydroxy-pentanoic    acid (TFA salt)-   28.    (2R,4R)-4-{[5-(2-Chloro-benzoylamino)-2H-pyrazole-3-carbonyl]-amino}-5-(3′-chloro-biphenyl-4-yl)-2-hydroxy-pentanoic    acid ethyl ester (TFA salt)-   29.    (2R,4R)-4-{[5-(2-Chloro-benzoylamino)-2H-pyrazole-3-carbonyl]-amino}-5-(3′-chloro-biphenyl-4-yl)-2-hydroxy-pentanoic    acid isobutyl ester (TFA salt)-   30.    (2R,4R)-4-{[5-(2-Chloro-benzoylamino)-2H-pyrazole-3-carbonyl]-amino}-5-(3′-chloro-biphenyl-4-yl)-2-hydroxy-pentanoic    acid isopropyl ester (TFA salt)-   31.    (2R,4R)-5-(3′-Chloro-biphenyl-4-yl)-2-hydroxy-4-{[5-(2-methoxy-benzoylamino)-2H-pyrazole-3-carbonyl]-amino}-pentanoic    acid-   32.    (2R,4R)-5-(3′-Chloro-biphenyl-4-yl)-2-hydroxy-4-{[5-(1-hydroxy-ethyl)-2H-pyrazole-3-carbonyl]-amino}-pentanoic    acid-   33.    (2R,4R)-5-(3′-Chloro-biphenyl-4-yl)-2-hydroxy-4-[(5-pyridin-3-yl-2H-pyrazole-3-carbonyl)-amino]-pentanoic    acid ethyl ester (TFA salt)

MS m/z: [M + H]⁺ Ex. R¹ R³ R⁴ Formula calcd found 34 —OH

H C₂₆H₂₃ClN₄O₄ 491.14 491.2 35 —OH —OH —CH₃ C₂₂H₂₂ClN₃O₅ 444.12 444.4 36—OCH₂—CH(CH₃) —OH —CH₃ C₂₆H₃₀ClN₃O₃ 500.19 500.0 37 —OH —OH

C₂₆H₂₃ClN₄O₅ 507.14 506.8 38 —OH —OH 2-fluoro-phenyl C₂₇H₂₃ClFN₃O₅524.13 523.8 39 —OH —OH 3-chloro-phenyl C₂₇H₂₃Cl₂N₃O₅ 540.10 539.6 40—OH —OCH₂—CH₃ H C₂₃H₂₄ClN₃O₅ 458.14 458.4

-   34.    (2R,4R)-5-(3′-Chlorobiphenyl-4-yl)-2-hydroxy-4-[(5-pyridin-3-yl-1H-pyrazole-3-carbonyl)-amino]-pentanoic    acid (TFA salt)-   35.    (2R,4R)-5-(3′-Chloro-biphenyl-4-yl)-2-hydroxy-4-[(5-hydroxy-1-methyl-1H-pyrazole-3-carbonyl)-amino]-pentanoic    acid-   36.    (2R,4R)-5-(3′-Chloro-biphenyl-4-yl)-2-hydroxy-4-[(5-hydroxy-1-methyl-1H-pyrazole-3-carbonyl)-amino]-pentanoic    acid isobutyl ester-   37.    (2R,4R)-5-(3′-Chloro-biphenyl-4-yl)-2-hydroxy-4-[(5-hydroxy-1-pyridin-2-yl-1H-pyrazole-3-carbonyl)-amino]-pentanoic    acid (TFA salt)-   38.    (2R,4R)-5-(3′-Chloro-biphenyl-4-yl)-4-{[1-(2-fluoro-phenyl)-5-hydroxy-1H-pyrazole-3-carbonyl]-amino}-2-hydroxy-pentanoic    acid-   39.    (2R,4S)-5-(3′-Chloro-biphenyl-4-yl)-4-{[1-(3-chloro-phenyl)-5-hydroxy-1H-pyrazole-3-carbonyl]-amino}-2-hydroxy-pentanoic    acid-   40.    (2R,4R)-5-(3′-Chloro-biphenyl-4-yl)-4-[(5-ethoxy-1H-pyrazole-3-carbonyl)-amino]-2-hydroxy-pentanoic    acid

MS m/z: [M + H]⁺ Ex. R¹ R³ R⁴ Formula calcd found 41 —OH ═O phenylC₂₇H₂₄ClN₃O₅ 506.14 506.2 42 —OH ═O 3-chlorophenyl C₂₆H₂₂Cl₂N₄O₅ 541.10540.6 43 —OH ═O 2-chlorophenyl C₂₆H₂₂Cl₂N₄O₅ 541.10 540.6 44 —OH ═O4-fluorophenyl C₂₆H₂₂ClFN₄O₅ 525.13 524.8

-   41.    (2R,4R)-5-(3′-Chlorobiphenyl-4-yl)-2-hydroxy-4-[(5-oxo-1-phenyl-2,5-dihydro-1H-pyrazole-3-carbonyl)-amino]-pentanoic    acid (TFA salt)-   42.    (2R,4R)-5-(3′-Chloro-biphenyl-4-yl)-4-{[1-(3-chloro-phenyl)-5-oxo-4,5-dihydro-1H-[1,2,4]triazole-3-carbonyl]-amino}-2-hydroxy-pentanoic    acid-   43.    (2R,4R)-5-(3′-Chloro-biphenyl-4-yl)-4-{[1-(2-chloro-phenyl)-5-oxo-4,5-dihydro-1H-[1,2,4]triazole-3-carbonyl]-amino}-2-hydroxy-pentanoic    acid-   44.    (2R,4R)-5-(3′-Chloro-biphenyl-4-yl)-4-{[1-(4-fluoro-phenyl)-5-oxo-4,5-dihydro-1H-[1,2,4]triazole-3-carbonyl]-amino}-2-hydroxy-pentanoic    acid

MS m/z: [M + H]⁺ Ex. R¹ R³ R⁴ Formula calcd found 45 —OH —CF₃ HC₂₁H₁₈ClF₃N₄O₄ 483.10 483.0

-   45.    (2R,4R)-5-(3′-Chlorobiphenyl-4-yl)-2-hydroxy-4-[(5-trifluoromethyl-4H-[1,2,4]triazole-3-carbonyl)-amino]-pentanoic    acid (TFA salt)

MS m/z: [M + H]⁺ Ex. R¹ R³ R⁴ Formula calcd found 46 —OH Cl HC₂₀H₁₈Cl₂N₄O₄ 449.07 449.0

-   46.    (2R,4R)-5-(3′-Chlorobiphenyl-4-yl)-4-[(5-chloro-1H-[1,2,4]triazole-3-carbonyl)-amino]-2-hydroxy-pentanoic    acid (TFA salt)

MS m/z: [M + H]⁺ Ex. R¹ R³ R⁴ Formula calcd found 47 —OH ═O phenylC₂₆H₂₃ClN₄O₅ 507.14 507.2

-   47.    (2R,4R)-5-(3′-Chlorobiphenyl-4-yl)-2-hydroxy-4-[(5-oxo-1-phenyl-4,5-dihydro-1H-[1,2,4]triazole-3-carbonyl)-amino]-pentanoic    acid (TFA salt)

MS m/z: [M + H]⁺ Ex. R¹ R³ R⁴ Formula calcd found 48 —OH ═O benzylC₂₉H₂₆ClN₃O₅ 532.16 532.2 49 —OH ═O phenyl C₂₈H₂₄ClN₃O₅ 518.14 518.2

-   48.    (2R,4R)-4-[(1-Benzyl-6-oxo-1,6-dihydro-pyridazine-3-carbonyl)-amino]-5-(3′-chlorobiphenyl-4-yl)-2-hydroxy-pentanoic    acid (TFA salt)-   49.    (2R,4R)-5-(3′-Chlorobiphenyl-4-yl)-2-hydroxy-4-[(6-oxo-1-phenyl-1,6-dihydro-pyridazine-3-carbonyl)-amino]-pentanoic    acid (TFA salt)

MS m/z: [M + H]⁺ Ex. R¹ R³ R⁴ Formula calcd found 50 —OH —OH HC₂₂H₂₀ClN₃O₅ 442.11 442.0

-   50.    (2R,4R)-5-(3′-Chlorobiphenyl-4-yl)-2-hydroxy-4-[(6-hydroxy-pyridazine-3-carbonyl)-amino]-pentanoic    acid (TFA salt)

Example 19

Following the procedures described in the examples herein, andsubstituting the appropriate starting materials and reagents, compoundshaving the following formula were prepared as the parent compound.

MS m/z: [M + H]⁺ Ex. R¹ R³ R⁴ b R⁶ Formula calcd found  1 —OH H —OH 22′,5′- C₂₀H₁₈Cl₂N₄O₅ 465.07 465.2 diCl  2 —OCH₂—CH(CH₃)₂ H —OH 2 2′,5′-C₂₄H₂₆Cl₂N₄O₅ 521.13 521.2 diCl  3 —OCH—(CH₃)₂ H —OH 2 2′,5′-C₂₃H₂₄Cl₂N₄O₅ 507.11 507.2 diCl  4 —O—CH₂CH₃ H —OH 2 2′,5′-C₂₂H₂₂Cl₂N₄O₅ 493.10 493.2 diCl  5 —O—(CH₂)₆—CH₃ H —OH 2 2′,5′-C₂₇H₃₂Cl₂N₄O₅ 563.18 563.2 diCl  6 —OH H —OH 2 2′-F, 5′-Cl C₂₀H₁₈ClFN₄O₅449.10 449.2  7 —OCH₂—CH(CH₃)₂ H —OH 2 2′-F, 5′-Cl C₂₄H₂₆ClFN₄O₅ 505.16505.2  8 —OCH—(CH₃)₂ H —OH 2 2′-F, 5′-Cl C₂₃H₂₄ClFN₄O₅ 491.14 491.4  9—O—CH₂CH₃ H —OH 2 2′-F, 5′-Cl C₂₂H₂₂ClFN₄O₅ 477.13 477.0 10—O—(CH₂)₆—CH₃ H —OH 2 2′-F, 5′-Cl C₂₇H₃₂ClFN₄O₅ 547.20 547.2 11—OCH—(CH₃)₂ H —O—CH₂O—C(O)—CH—(CH₃)₂—NH₂ 2 2′-F, 5′-Cl C₂₉H₃₅ClFN₅O₇620.22 620.0 12 —OH H —OH 2 2′-CH₃, 5′-Cl C₂₁H₂₁ClN₄O₅ 445.12 445.4 13—OCH₂—CH(CH₃)₂ H —OH 2 2′-CH₃, 5′-Cl C₂₅H₂₉ClN₄O₅ 501.18 501.4 14—OCH—(CH₃)₂ H —OH 2 2′-CH₃, 5′-Cl C₂₄H₂₇ClN₄O₅ 487.17 487.4 15 —O—CH₂CH₃H —OH 2 2′-CH₃, 5′-Cl C₂₃H₂₅ClN₄O₅ 473.15 473.2 16 —O—(CH₂)₆—CH₃ H —OH 22′-CH₃, 5′-Cl C₂₈H₃₅ClN₄O₅ 543.23 543.4 17 —OH H —OH 1 2′- C₂₁H₂₂N₄O₆427.15 427.2 OCH₃

-   1.    (2R,4R)-5-(2′,5′-Dichlorobiphenyl-4-yl)-2-hydroxy-4-[(1-hydroxy-1H-[1,2,3]triazole-4-carbonyl)-amino]-pentanoic    acid-   2.    (2R,4R)-5-(2′,5′-Dichloro-biphenyl-4-yl)-2-hydroxy-4-[(1-hydroxy-1H-[1,2,3]triazole-4-carbonyl)-amino]-pentanoic    acid isobutyl ester-   3.    (2R,4R)-5-(2′,5′-Dichloro-biphenyl-4-yl)-2-hydroxy-4-[(1-hydroxy-1H-[1,2,3]triazole-4-carbonyl)-amino]-pentanoic    acid isopropyl ester-   4.    (2R,4R)-5-(2′,5′-Dichloro-biphenyl-4-yl)-2-hydroxy-4-[(1-hydroxy-1H-[1,2,3]triazole-4-carbonyl)-amino]-pentanoic    acid ethyl ester-   5.    (2R,4R)-5-(2′,5′-Dichloro-biphenyl-4-yl)-2-hydroxy-4-[(1-hydroxy-1H-[1,2,3]triazole-4-carbonyl)-amino]-pentanoic    acid heptyl ester-   6.    (2R,4R)-5-(5′-Chloro-2′-fluorobiphenyl-4-yl)-2-hydroxy-4-[(1-hydroxy-1H-[1,2,3]triazole-4-carbonyl)-amino]-pentanoic    acid-   7.    (2R,4R)-5-(5′-Chloro-2′-fluorobiphenyl-4-yl)-2-hydroxy-4-[(1-hydroxy-1H-[1,2,3]triazole-4-carbonyl)-amino]-pentanoic    acid isobutyl ester-   8.    (2R,4R)-5-(5′-Chloro-2′-fluorobiphenyl-4-yl)-2-hydroxy-4-[(1-hydroxy-1H-[1,2,3]triazole-4-carbonyl)-amino]-pentanoic    acid isopropyl ester-   9.    (2R,4R)-5-(5′-Chloro-2′-fluorobiphenyl-4-yl)-2-hydroxy-4-[(1-hydroxy-1H-[1,2,3]triazole-4-carbonyl)-amino]-pentanoic    acid ethyl ester-   10.    (2R,4R)-5-(5′-Chloro-2′-fluorobiphenyl-4-yl)-2-hydroxy-4-[(1-hydroxy-1H-[1,2,3]triazole-4-carbonyl)-amino]-pentanoic    acid heptyl ester-   11.    (2R,4R)-4-{[1-((S)-2-Amino-3-methyl-butyryloxymethoxy)-1H-[1,2,3]triazole-4-carbonyl]-amino}-5-(5′-chloro-2′-fluoro-biphenyl-4-yl)-2-hydroxy-pentanoic    acid isopropyl ester-   12.    (2R,4R)-5-(5′-Chloro-2′-methyl-biphenyl-4-yl)-2-hydroxy-4-[(1-hydroxy-1H-[1,2,3]triazole-4-carbonyl)-amino]-pentanoic    acid-   13.    (2R,4R)-5-(5′-Chloro-2′-methyl-biphenyl-4-yl)-2-hydroxy-4-[(1-hydroxy-1H-[1,2,3]triazole-4-carbonyl)-amino]-pentanoic    acid isobutyl ester-   14.    (2R,4R)-5-(5′-Chloro-2′-methyl-biphenyl-4-yl)-2-hydroxy-4-[(1-hydroxy-1H-[1,2,3]triazole-4-carbonyl)-amino]-pentanoic    acid isopropyl ester-   15.    (2R,4R)-5-(5′-Chloro-2′-methyl-biphenyl-4-yl)-2-hydroxy-4-[(1-hydroxy-1H-[1,2,3]triazole-4-carbonyl)-amino]-pentanoic    acid ethyl ester-   16.    (2R,4R)-5-(5′-Chloro-2′-methyl-biphenyl-4-yl)-2-hydroxy-4-[(1-hydroxy-1H-[1,2,3]triazole-4-carbonyl)-amino]-pentanoic    acid heptyl ester-   17.    (2R,4R)-2-Hydroxy-4-[(1-hydroxy-1H-[1,2,3]triazole-4-carbonyl)-amino]-5-(2′-methoxy-biphenyl-4-yl)-pentanoic    acid

MS m/z: [M + H]⁺ Ex. R¹ R³ R⁴ b R⁶ Formula calcd found 18 —OH H—OCH₂O—C(O)—CH₃ 2 2′-F, 5′-Cl C₂₃H₂₂ClFN₄O₇ 521.12 521.1

-   18.    (2R,4R)-4-[(3-Acetoxymethoxy-3H-[1,2,3]triazole-4-carbonyl)-amino]-5-(5′-chloro-2′-fluoro-biphenyl-4-yl)-2-hydroxy-pentanoic    acid

MS m/z: [M + H]⁺ Ex. R¹ R³ R⁴ b R⁶ Formula calcd found 19 —OH —OCH₃ H 22′-F, 5′-Cl C₂₂H₂₀ClFN₂O₆ 463.10 463.2

-   19.    (2R,4R)-5-(5′-Chloro-2′-fluoro-biphenyl-4-yl)-2-hydroxy-4-[(3-methoxy-isoxazole-5-carbonyl-amino]-pentanoic    acid

MS m/z: [M + H]⁺ Ex. R¹ R³ R⁴ b R⁶ Formula calcd found 20 —OH ═O phenyl2 2′-F, 5′-Cl C₂₆H₂₂ClFN₄O₅ 525.13 525.2

-   20.    (2R,4R)-5-(5′-Chloro-2′-fluoro-biphenyl-4-yl)-2-hydroxy-4-[(5-oxo-1-phenyl-4,5-dihydro-1H-[1,2,4]triazole-3-carbonyl)-amino]-pentanoic    acid

MS m/z: [M + H]⁺ Ex. R¹ R⁴ b R⁶ Formula calcd found 21 —OH—OCH₂O—C(O)—CH₃ 2 2′,5′-diCl C₂₇H₂₄Cl₂N₄O₇ 587.10 587.1 22—OCH₂CH—(CH₃)₂ —OCH₂O—C(O)CH—(CH₃)₂NH₂ 1 3′-Cl C₃₄H₄₀ClN₅O₇ 666.26 666.0

-   21.    (2R,4R)-4-[(3-Acetoxymethoxy-3H-benzotriazole-5-carbonyl)-amino]-5-(2′,5-dichloro-biphenyl-4-yl)-2-hydroxy-pentanoic    acid-   22.    (2R,4R)-4-{[3-((S)-2-Amino-3-methyl-butyryloxymethoxy)-3H-benzotriazole-5-carbonyl]-amino}-5-(3′-chloro-biphenyl-4-yl)-2-hydroxy-pentanoic    acid isobutyl ester

Example 20

Following the procedures described in the examples herein, andsubstituting the appropriate starting materials and reagents, compoundshaving the following formula were prepared as the parent compound or asa TFA salt.

MS m/z: [M + H]⁺ Ex. R³ R⁴ R⁵ Formula calcd found 1 H H Cl C₂₀H₁₉ClN₄O₄415.11 415.4

-   1.    (2R,4R)-5-(3-Chlorobiphenyl-4-yl)-2-hydroxy-4-[(1H-[1,2,3]triazole-4-carbonyl)-amino]-pentanoic    acid (TFA salt)

MS m/z: [M + H]⁺ Ex. R³ R⁴ R⁵ Formula calcd found 1 H H Cl C₂₀H₁₉ClN₄O₄415.11 415.2

-   2.    (2R,4R)-5-(3-Chlorobiphenyl-4-yl)-2-hydroxy-4-[(3H-[1,2,3]triazole-4-carbonyl)-amino]-pentanoic    acid

MS m/z: [M + H]⁺ Ex. R³ R⁴ R⁵ Formula calcd found 3 ═O 3- ClC₂₆H₂₂Cl₂N₄O₅ 541.10 541.2 chlorophenyl 4 ═O phenyl Cl C₂₆H₂₃ClN₄O₅507.14 507.2

-   3.    (2R,4R)-5-(3-Chloro-biphenyl-4-yl)-4-{[1-(3-chloro-phenyl)-5-oxo-4,5-dihydro-1H-[1,2,4]triazole-3-carbonyl]-amino}-2-hydroxy-pentanoic    acid-   4.    (2R,4R)-5-(3-Chloro-biphenyl-4-yl)-2-hydroxy-4-[(5-oxo-1-phenyl-4,5-dihydro-1H-[1,2,4]triazole-3-carbonyl)-amino]-pentanoic    acid

MS m/z: [M + H]⁺ Ex. R³ R⁴ R⁵ Formula calcd found 5 —C(O)N(CH₃)₂ H ClC₂₄H₂₅ClN₄O₅ 485.15 486.2 6 —C(O)N(CH₃)—[(CH₂)₂OCH₃] H Cl C₂₆H₂₉ClN₄O₆529.18 529.2 7 —C(O)—CH₃ H Cl C₂₃H₂₂ClN₃O₅ 456.12 456.2 8

H Cl C₂₆H₂₃ClN₄O₄ 491.14 491.2 9

H Cl C₂₆H₂₃ClN₄O₄ 491.14 493.2

-   5.    (2R,4R)-5-(3-Chloro-biphenyl-4-yl)-4-[(5-dimethylcarbamoyl-2H-pyrazole-3-carbonyl)-amino]-2-hydroxy-pentanoic    acid-   6.    (2R,4R)-5-(3-Chloro-biphenyl-4-yl)-2-hydroxy-4-({5-[(2-methoxy-ethyl)-methyl-carbamoyl]-2H-pyrazole-3-carbonyl}-amino)-pentanoic    acid-   7.    (2R,4R)-4-[(5-Acetyl-2H-pyrazole-3-carbonyl)-amino]-5-(3-chloro-biphenyl-4-yl)-2-hydroxy-pentanoic    acid-   8.    (2R,4R)-5-(3-Chloro-biphenyl-4-yl)-2-hydroxy-4-[(5-pyridin-3-yl-2H-pyrazole-3-carbonyl)-amino]-pentanoic    acid (TFA salt)-   9.    (2R,4R)-5-(3-Chloro-biphenyl-4-yl)-2-hydroxy-4-[(5-pyridin-2-yl-2H-pyrazole-3-carbonyl)-amino]-pentanoic    acid (TFA salt)

Example 21

Following the procedures described in the examples herein, andsubstituting the appropriate starting materials and reagents, compoundshaving the following formula were prepared as the parent compound.

MS m/z: [M + H]⁺ Ex. R³ R⁴ R⁵ R⁶ Formula calcd found 1 H H Cl ClC₂₀H₁₈Cl₂N₄O₄ 449.07 449.0

-   1.    (2R,4R)-5-(3,3′-Dichlorobiphenyl-4-yl)-2-hydroxy-4-[(3H-[1,2,3]triazole-4-carbonyl)-amino]-pentanoic    acid

MS m/z: [M + H]⁺ Ex. R³ R⁴ R⁵ R⁶ Formula calcd found 2 —CH₂OCH₃ H Cl ClC₂₃H₂₃Cl₂N₃O₅ 492.10 492.2

-   2.    (2R,4R)-5-(3,3′-Dichloro-biphenyl-4-yl)-2-hydroxy-4-[(5-methoxymethyl-2H-pyrazole-3-carbonyl)-amino]-pentanoic    acid

Preparation 13(2R,4R)-5-(4-Bromophenyl)-2-hydroxy-4-[(3-hydroxy-3H-benzotriazole-5-carbonyl)-amino]-pentanoicAcid Ethyl Ester

HCTU (837 mg, 2.0 mmol) was added to a solution of1-hydroxy-1H-1,2,3-benzotriazole-6-carboxylic acid (362 mg, 2.0 mmol)and the mixture was stirred at room temperature for 10 minutes. DIPEA(529 μL, 3.0 mmol) and(2R,4R)-4-amino-5-(4-bromophenyl)-2-hydroxy-pentanoic acid ethyl ester(320 mg, 1.0 mmol) were then added and the resulting mixture was stirredat room temperature for 15 minutes. The mixture was concentrated invacuo and the resulting residue was purified (C18 column, 55 g, 20-70%MeCN in water with 5% TFA) to yield the title compound as a white solid365 mg).

Example 22(2R,4R)-5-(5′-Chloro-2′-fluorobiphenyl-4-yl)-2-hydroxy-4-[(3-hydroxy-3H-benzotriazole-5-carbonyl)-amino]-pentanoicAcid

SilicaCat®DPP-Pd (0.3 mmol/g loading; 37.4 mg, 10 μmol) was added to asolution of(2R,4R)-5-(4-bromophenyl)-2-hydroxy-4-[(3-hydroxy-3H-benzotriazole-5-carbonyl)-amino]-pentanoicacid ethyl ester (50.0 mg, 105 μmol), the phenyl boronic acid (157 μmol,1.5 eq.) and K₂CO₃ (43.4 mg, 314 μmol) in EtOH (500 L) and water (150L), and the reaction mixture was heated at 100° C. for 10 minutes. Themixture was allowed to cool to room temperature, after which 1.0 M ofLiOH in water (838 μL, 838 μmol) was added and the mixture was stirredfor 30 minutes. The mixture was filtered, the filtrate was concentratedin vacuo and purified by preparative HPLC to yield the title compound(17.9 mg; purity 98%). MS m/z [M+H]⁺ calc'd for C₂₄H₂₀ClFN₄O₅, 499.11;found 499.2.

Example 23

Following the procedures described in the examples herein, andsubstituting the appropriate starting materials and reagents, compoundshaving the following formula were prepared as the parent compound or asa TFA salt.

MS m/z: [M + H]⁺ Ex. R¹ a R⁶ Formula calcd found 1 —OH 1 3′-CH₃C₂₅H₂₄N₄O₅ 461.17 461.2 2 —OH 2 2′-CH_(3,) C₂₅H₂₄ClN₄O₅ 496.14 495.25′-Cl 3 —OH 1 2′-OCH₃ C₂₅H₂₄N₄O₆ 477.17 477.2 4 —OH 2 2′,5′-diClC₂₄H₂₀Cl₂N₄O₅ 515.08 515.0 5 —OCH₂CH₃ 2 2′,5′-diCl C₂₆H₂₄Cl₂N₄O₅ 543.11543.2 6 —OCH₂CH(CH₃)₂ 2 2′,5′-diCl C₂₈H₂₈Cl₂N₄O₅ 571.14 571.2 7—OCH(CH₃)₂ 2 2′,5′-diCl C₂₇H₂₆Cl₂N₄O₅ 557.13 557.1 8 —OH 2 3′-Cl,C₂₄H₂₁ClN₄O₆ 497.12 497.2 5′-OH

-   1.    (2S,4S)-2-Hydroxy-4-[(3-hydroxy-3H-benzotriazole-5-carbonyl)-amino]-5-(3′-methyl-biphenyl-4-yl)-pentanoic    acid-   2.    (2S,4S)-5-(5′-Chloro-2′-methyl-biphenyl-4-yl)-2-hydroxy-4-[(3-hydroxy-1H-benzotriazole-5-carbonyl)-amino]-pentanoic    acid-   3.    (2S,4S)-2-Hydroxy-4-[(3-hydroxy-3H-benzotriazole-5-carbonyl)-amino]-5-(2′-methoxy-biphenyl-4-yl)-pentanoic    acid-   4.    (2S,4S)-5-(2′,5′-Dichlorobiphenyl-4-yl)-2-hydroxy-4-[(3-hydroxy-3H-benzotriazole-5-carbonyl)-amino]-pentanoic    acid-   5.    (2R,4R)-5-(2′,5′-Dichlorobiphenyl-4-yl)-2-hydroxy-4-[(3-hydroxy-3H-benzotriazole-5-carbonyl)-amino]-pentanoic    acid ethyl ester-   6.    (2R,4R)-5-(2′,5′-Dichlorobiphenyl-4-yl)-2-hydroxy-4-[(3-hydroxy-3H-benzotriazole-5-carbonyl)-amino]-pentanoic    acid isobutyl ester-   7.    (2R,4R)-5-(2′,5′-Dichlorobiphenyl-4-yl)-2-hydroxy-4-[(3-hydroxy-3H-benzotriazole-5-carbonyl)-amino]-pentanoic    acid isopropyl ester (TFA salt)-   8.    (2S,4S)-5-(3′-Chloro-5′-hydroxy-biphenyl-4-yl)-2-hydroxy-4-[(3-hydroxy-3H-benzotriazole-5-carbonyl)-amino]-pentanoic    acid

Preparation 14(S)-2-(1-Biphenyl-4-yl-1-methylethyl)-5-oxo-pyrrolidine-1-carboxylicAcid t-Butyl Ester

To a solution of 2-(4-bromophenyl)acetonitrile (130.0 g, 0.7 mol) andiodomethane (103.9 mL, 1.7 mol) in THF (1.0 L) was added NaH (60%dispersion in mineral oil, 66.7 g, 1.7 mol) in small portions at 10° C.After completion of the addition, the mixture was stirred at 10° C. foranother 2 hours. The mixture was poured into ice water (2.0 L) andextracted with EtOAc (1.5 L). The organic layer was washed withsaturated aqueous NaCl, dried over anhydrous MgSO₄ and concentrated toyield compound 1 (175 g, containing mineral oil) as a yellow oil, whichwas used directly without further purification. ¹H NMR (CDCl₃, 300 MHz)δ 7.52 (d, J=9.0 Hz, 2H), 7.38 (d, J=9.0 Hz, 2H), 1.72 (s, 6H).

To a solution of compound 1 (175 g, containing mineral oil) in DCM (1.0L) was added DIBAL (1.0 M solution in DCM, 700 mL, 0.70 mol) dropwise at−78° C. The reaction mixture was stirred at −78° C. for 1.5 hours andthen quenched carefully with 3.0 N HCl (1.0 L). The resulting mixturewas stirred at room temperature overnight and the organic layer waswashed with saturated aqueous NaCl, dried over anhydrous Na₂SO₄ andconcentrated to yield compound 2 (180 g) as a yellow oil, which was useddirectly without further purification. ¹H NMR (CDCl₃, 300 MHz) δ 9.48(s, 1H), 7.53 (d, J=11.0 Hz, 2H), 7.17 (d, J=11.0 Hz, 2H), 1.46 (s, 6H).

To an aqueous solution of NaCN (32.7 g in 1.0 L of H₂O, 0.7 mol) wereadded (NH₄)₂CO₃ (380 g, 4.0 mol) and compound 2 (180 g). The reactionmixture was refluxed overnight and then concentrated under reducedpressure at 75° C. Water (350 mL) was added to the residue and themixture was concentrated again. The residue was suspended in petroleumether (700 mL) and water (250 mL) and the resulting mixture was stirredat room temperature for 15 minutes. The precipitate was collected byfiltration and dried to yield compound 3 (150 g) as a white solid. ¹HNMR (DMSO-d6, 300 MHz) δ 10.39 (s, 1H), 8.05 (s, 1H), 7.48 (d, J=9.0 Hz,2H), 7.28 (d, J=9.0 Hz, 2H), 4.17 (s, 1H), 1.42 (s, 3H), 1.34 (s, 3H).

A suspension of compound 3 (150 g, 0.51 mol) in 6.0 N NaOH (400 mL) andethane-1,2-diol (300 mL) was stirred at 120° C. for 38 hours. Themixture was cooled to room temperature and neutralized with an HClsolution. The precipitate was collected by filtration and dried to yieldcompound 4 (250 g, containing NaCl salt) as a white solid. 1H NMR(DMSO-d6, 300 MHz) δ 7.35 (d, J=9.0 Hz, 2H), 7.17 (d, J=9.0 Hz, 2H),3.22 (s, 1H), 1.16 (s, 3H), 1.15 (s, 3H).

To a suspension of compound 4 (250 g, containing NaCl salt) in MeOH (1.0L) was added thionyl chloride (72.0 mL, 1.0 mol) dropwise at 5° C. Themixture was refluxed overnight and the solvent was removed under reducedpressure. The residue was partitioned between DCM (1.0 L) and saturatedaqueous NaHCO₃ (1.5 L). The organic layer was washed with saturatedaqueous NaCl, dried over anhydrous Na₂SO₄ and concentrated to yield thecorresponding methyl ester (90.0 g). 2-Phenylacetyl chloride (48.6 g,0.32 mol) was added dropwise to a solution of the ester (90.0 g) andEt₃N (56.5 mL, 0.41 mol) in DCM (1.0 L) at 0° C. and the mixture wasstirred at 0° C. for 30 minutes. The mixture was washed with 1.0 N HCl(500 mL) and saturated aqueous NaCl, respectively. The organic layer wasdried over anhydrous Na₂SO₄ and concentrated to yield compound 5 (120g). ¹H NMR (CDCl₃, 300 MHz) δ 7.32 (m, 5H), 7.18 (m, 2H), 6.95 (m, 2H),5.68 (br s, 1H), 4.76 (d, J=9.0 Hz, 1H), 3.57 (s, 3H), 3.53 (d, J=5.0Hz, 2H), 1.30 (s, 3H), 1.25 (s, 3H).

To a solution of compound 5 (120 g, 0.30 mol) in MeOH (500 mL) was added4.0 N NaOH (200 mL). The mixture was stirred at room temperature for 4hours and then the 15 pH was adjusted to pH=1 with 3.0 N HCl. Theresulting mixture was extracted with EtOAc (2×300 mL). The combinedextracts were washed with saturated aqueous NaCl, dried over anhydrousNa₂SO₄, and concentrated under reduced pressure. The residue wasrecrystallized from EtOAc/hexanes to yield compound 6 (82.0 g). ¹H NMR(DMSO-d6, 300 MHz) δ 7.41 (d, J=6.0 Hz, 2H), 7.22 (m, 5H), 6.99 (d,J=6.0 Hz, 2H), 4.65 (d, J=9.0 Hz, 1H), 3.52 (d, J=14.0 Hz, 1H), 3.36 (d,J=14.0 Hz, 1H), 1.34 (s, 3H), 1.30 (s, 3H).

A suspension of compound 6 (82.0 g, 0.21 mol) in distilled water (3.0 L)was adjusted to pH=8.5 with 3.0 N LiOH and a clear solution was formed.Immobilized Penicillinase (20.0 g) was added and the resulting mixturewas stirred at 37° C. for 60 hours. The mixture was filtered and thefiltrate was adjusted to pH=1 with 3.0 N HCl and extracted with EtOAc.The combined extracts were washed with saturated aqueous NaCl, driedover anhydrous Na₂SO₄ and concentrated to yield compound 7 (59.0 g, 80%ee, containing 2-phenylacetic acid).

A suspension of compound 7 (59.0 g, containing 2-phenylacetic acid) in6.0 N HCl (500 mL) was refluxed overnight. The mixture was washed withEtOAc (300 mL) and the aqueous phase was concentrated under reducedpressure to yield the corresponding amino acid as its hydrochloridesalt. The salt was dissolved in water (300 mL) and the solution wasadjusted to pH=11. A solution of (Boc)₂O (33.0 g, 0.2 mol) in acetone(200 mL) was added and the mixture was stirred at room temperature for 2hours. The mixture was washed with hexanes (200 mL) and the aqueousphase was adjusted to pH=2. The resulting mixture was extracted withEtOAc (2×300 mL). The combined extracts were washed with saturatedaqueous NaCl, dried over anhydrous Na₂SO₄ and concentrated to yieldcompound 8 (37.0 g) as a white solid. ¹H NMR (CDCl₃, 300 MHz) δ 9.48 (brs, 1H), 7.46 (d, J=7.0 Hz, 2H), 7.26 (d, J=7.0 Hz, 2H), 5.02 (br s, 1H),4.56 (d, J=9.0 Hz, 1H), 1.39 (s, 9H).

A mixture of compound 8 (37.0 g, 0.1 mol) in dioxane (200 mL) and 1.0 NK₂CO₃ (200 mL) was degassed for 30 minutes with nitrogen, followed bythe addition of phenylboronic acid (13.4 g, 0.1 mol) and Pd(PPh₃)₄(1.6g, 1.4 mmol). The mixture was heated at 75° C. for 8 hours and thencooled to room temperature. The mixture was washed with EtOAc/hexanes(150 mL, 1:1) and the aqueous phase was adjusted to pH=2 and extractedwith EtOAc (2×300 mL). The combined extracts were washed with saturatedaqueous NaCl, dried over anhydrous Na₂SO₄ and concentrated to yieldcompound 9 (31.0 g, 84% yield) as a white solid.

A solution of compound 9 (31.0 g, 84 mmol), Meldrum's acid (13.3 g, 92mmol) and DMAP (15.4 g, 0.13 mol) in DCM (400 mL) was cooled to −5° C.and a solution of DCC (19.0 g, 92 mmol) in DCM (200 mL) was added over 1hour. The mixture was stirred at −5° C. overnight. The precipitate wasfiltered off and the filtrate was washed with 1.0 N HCl (2×700 mL) andsaturated aqueous NaCl, respectively. After the organic layer containingcompound 10 was dried over anhydrous MgSO₄, it was used directly for thenext step without concentration.

A solution of compound 10 in DCM (600 mL) was cooled to −5° C. and AcOH(45.0 mL) was added. Then NaBH₄ (7.0 g, 0.2 mol) was added in smallportions over 30 minutes and the mixture was stirred at −5° C. for 3hours. Water (50.0 mL) was added dropwise followed by addition ofsaturated aqueous NaCl (450 mL). The organic layer was washed with water(2×300 mL) and saturated aqueous NaHCO₃ (2×300 mL), dried over anhydrousMgSO₄ and concentrated to yield compound 11 (32.0 g, 75% ee) as anoff-white solid. After recrystallization from EtOH, chirally purecompound 11 (13.0 g) was obtained. ¹H NMR (CDCl₃, 300 MHz) δ 7.61 (m,10OH), 4.46 (br s, 1H), 4.26 (m, 1H), 3.72 (br s, 1H), 2.23 (m, 1H),1.79 (s, 3H), 1.76 (s, 3H), 1.48 (s, 6H), 1.39 (s, 9H).

A solution of compound 11 (13.0 g, 27.0 mmol) in toluene (100.0 mL) wasrefluxed for 3 hours. After evaporation of the solvent, the residue wasrecrystallized from hexanes/EtOAc (3:1) to yield the title compound (8.0g) as a white solid.

Preparation 15(2R,4S)-4-Amino-5-biphenyl-4-yl-2-hydroxy-5-methylhexanoic Acid EthylEster

A mixture of(S)-2-(1-biphenyl-4-yl-1-methylethyl)-5-oxo-pyrrolidine-1-carboxylicacid t-butyl ester (14.0 g, 36.9 mmol, racemic) in a 3.0 N HCl-EtOAcsolution (150 mL) was stirred at room temperature for 3 hours. Thesolvent was removed under reduced pressure to yield compound 1 (10.0 g)as a white solid.

To a solution of compound 1 (10.0 g, 35.8 mmol) in THF (80.0 mL) wasadded BuLi (2.5 M in hexanes, 15.0 mL) dropwise at −78° C. After themixture was stirred for 30 minutes pivaloyl chloride (4.8 mL, 39.4 mmol)was added dropwise. The mixture was stirred at −78° C. for 1 hour andthen quenched with saturated aqueous NH₄Cl. The resulting mixture wasextracted with EtOAc and the combined extracts were washed withsaturated aqueous NaCl, dried over anhydrous MgSO₄ and concentrated. Theresidue was purified by flash column chromatography on silica gel toyield compound 2 (9.0 g) as a white solid.

To a solution of compound 2 (9.0 g, 24.7 mmol) in THF (50.0 mL) wasadded sodium bis(trimethylsilyl)amide (2.0 M in THF, 18.5 mL, 37.0 mmol)dropwise at −78° C. The mixture was stirred for 20 minutes and asolution of oxaziridine derivative (10.8 g, 37.0 mmol) in THF (30.0 mL)was added dropwise. The mixture was stirred at −78° C. for 30 minutesand then quenched with saturated aqueous NH₄Cl. The resulting mixturewas extracted with EtOAc (1.0 L) and the extract was washed with 1.0 NHCl and saturated aqueous NaCl, dried over anhydrous MgSO₄ andevaporated to remove most of the solvent. The precipitate was filteredoff and the filtrate was concentrated. The residue was purified by flashcolumn chromatography on silica gel (DCM:hexanes=1:1 to DCM) to yieldcompound 3 (4.3 g, racemic). This racemate was subjected to chiralAD-column chromatography to afford chirally pure compound 3 (1.4 g). ¹HNMR (DMSO-d6, 300 MHz) δ 7.63 (m, 4H), 7.49 (m, 4H), 4.83 (d, 1H), 3.29(m, 1H), 2.31 (m, 2H), 1.40 (s, 3H), 1.36 (s, 3H), 1.28 (s, 9H). LC-MS(ESI): m/z 380.1 [M+H]+.

A solution of compound 3 (1.7 g, 160 mmol) in EtOH (15.0 mL) and 12.0 NHCl (15.0 mL) was heated at 90-95° C. for 20 hours. The solvent wasremoved and the residue was treated with a 3.0 N HCl-EtOH solution (25.0mL) under reflux for another 3 hours. After removal of the solvent, theresidue was purified by preparative HPLC to yield the title compound(0.6 g) as a foamy solid HCl salt. ¹H NMR (DMSO-d6, 300 MHz) δ 7.88 (brs, 3H), 7.68 (m, 4H), 7.49 (m, 4H), 7.35 (m, 1H), 6.11 (br s, 1H), 4.11(br s, 1H), 4.05 (q, 2H), 3.61 (br s, 1H), 1.67 (m, 2H), 1.40 (s, 3H),1.36 (s, 3H), 1.09 (t, 3H). LC-MS (ESI): m/z 342.1 [M+H]+.

Example 245-[(S)-2-Biphenyl-4-yl-1-((R)-2-carboxy-2-hydroxy-ethyl)-2-methyl-propylcarbamoyl]-1H-pyrazole-3-carboxylicAcid

(2R,4S)-4-Amino-5-biphenyl-4-yl-2-hydroxy-5-methyl-hexanoic acid ethylester (70 mg, 0.2 mmol), 3,5-pyrazoledicarboxylic acid (32 mg, 0.2mmol), and HCTU (85 mg, 0.2 mmol) were combined in DMF (5 mL) andstirred for 2 minutes. DIPEA (79 mg, 0.6 mmol) was added and theresulting mixture was stirred for 1 hour at 50° C. The reaction mixturewas evaporated under reduced pressure. The crude material was dissolvedin EtOH, and add enough equivalents of 10N NaOH were added to make themixture basic. The reaction was monitor closely over 1 hour until finaldeprotection is complete. The mixture was then re-acidified with anequal volume of acetic acid and evaporated under reduced pressure. Theproduct was purified using reverse phase chromatography (10-70% MeCNgradient) to yield the title compound as a TFA salt (14 mg; purity 90%).MS m/z [M+H]⁺ calc'd for C₂₄H₂₅N₃O₆, 452.17; found 452.2.

Example 25

Following the procedures described in the examples herein, andsubstituting the appropriate starting materials and reagents, compoundshaving the following formula were prepared as the parent compound or asa TFA salt.

MS m/z: [M + H]⁺ Ex. —XR³R⁴ Formula calcd found 1

C₂₂H₂₄N₄O₄ 409.18 409.4 2

C₂₂H₂₄N₄O₅ 425.17 425.2 3

C₂₃H₂₄N₂O₆ 425.16 425.2

-   1.    (2R,4S)-5-Biphenyl-4-yl-2-hydroxy-5-methyl-4-[(1H-[1,2,3]triazole-4-carbonyl)-amino]-hexanoic    acid (TFA salt)-   2.    (2R,4S)-5-Biphenyl-4-yl-2-hydroxy-4-[(1-hydroxy-1H-[1,2,3]triazole-4-carbonyl)-amino]-5-methyl-hexanoic    acid (TFA salt)-   3.    (2R,4S)-5-Biphenyl-4-yl-2-hydroxy-4-[(3-hydroxy-isoxazole-5-carbonyl)-amino]-5-methyl-hexanoic    acid

Assay 1 In Vitro Assays for the Quantitation of Inhibitor Potencies atHuman and Rat NEP, and Human ACE

The inhibitory activities of compounds at human and rat neprilysin (EC3.4.24.11; NEP) and human angiotensin converting enzyme (ACE) weredetermined using in vitro assays as described below.

Extraction of NEP Activity from Rat Kidneys

Rat NEP was prepared from the kidneys of adult Sprague Dawley rats.Whole kidneys were washed in cold phosphate buffered saline (PBS) andbrought up in ice-cold lysis buffer (1% Triton X-114, 150 mM NaCl, 50 mMtris(hydroxymethyl) aminomethane (Tris) pH 7.5; Bordier (1981) J. Biol.Chem. 256: 1604-1607) in a ratio of 5 mL of buffer for every gram ofkidney. Samples were homogenized on ice using a polytron hand heldtissue grinder. Homogenates were centrifuged at 1000×g in a swingingbucket rotor for 5 minutes at 3° C. The pellet was resuspended in 20 mLof ice cold lysis buffer and incubated on ice for 30 minutes. Samples(15-20 mL) were then layered onto 25 mL of ice-cold cushion buffer (6%w/v sucrose, 50 mM pH 7.5 Tris, 150 mM NaCl, 0.06%, Triton X-114),heated to 37° C. for 3-5 minutes and centrifuged at 1000×g in a swingingbucket rotor at room temperature for 3 minutes. The two upper layerswere aspirated off, leaving a viscous oily precipitate containing theenriched membrane fraction. Glycerol was added to a concentration of 50%and samples were stored at −20° C. Protein concentrations werequantitated using a BCA detection system with bovine serum albumin (BSA)as a standard.

Enzyme Inhibition Assays

Recombinant human NEP and recombinant human ACE were obtainedcommercially (R&D Systems, Minneapolis, Minn., catalog numbers 1182-ZNand 929-ZN, respectively). The fluorogenic peptide substrateMca-D-Arg-Arg-Leu-Dap-(Dnp)-OH (Medeiros et al. (1997) Braz. J. Med.Biol. Res. 30:1157-62; Anaspec, San Jose, Calif.) andAbz-Phe-Arg-Lys(Dnp)-Pro-OH (Araujo et al. (2000) Biochemistry39:8519-8525; Bachem, Torrance, Calif.) were used in the NEP and ACEassays respectively.

The assays were performed in 384-well white opaque plates at 37° C.using the fluorogenic peptide substrates at a concentration of 10 μM inAssay Buffer (NEP: 50 mM HEPES, pH 7.5, 100 mM NaCl, 0.01% polyethyleneglycol sorbitan monolaurate (Tween-20), 10 μM ZnSO₄; ACE: 50 mM HEPES,pH 7.5, 100 mM NaCl, 0.01% Tween-20, 1 μM ZnSO₄). The respective enzymeswere used at concentrations that resulted in quantitative proteolysis of1 μM of substrate after 20 minutes at 37° C.

Test compounds were assayed over the range of concentrations from 10 μMto 20 pM. Test compounds were added to the enzymes and incubated for 30minute at 37° C. prior to initiating the reaction by the addition ofsubstrate. Reactions were terminated after 20 minutes of incubation at37° C. by the addition of glacial acetic acid to a final concentrationof 3.6% (v/v).

Plates were read on a fluorometer with excitation and emissionwavelengths set to 320 nm and 405 nm, respectively. Inhibition constantswere obtained by nonlinear regression of the data using the equation(GraphPad Software, Inc., San Diego, Calif.):

v=v ₀/[1+(I/K′)]

where v is the reaction rate, v₀ is the uninhibited reaction rate, I isthe inhibitor concentration and K′ is the apparent inhibition constant.

Compounds of the invention were tested in this assay and found to havepK_(i) values at human NEP as follows. In general, either the prodrugcompounds did not inhibit the enzyme in this in vitro assay, or theprodrugs were not tested (n.d.) since activity would not be expected.

Ex. pK_(i)  1-A n.d.  1-B ≥9.0  1-C n.d.  1-D n.d.  1-E n.d.  1-F n.d. 1-G n.d.  2-A n.d.  2-B n.d.  2-C ≥9.0  2-D ≥9.0  2-E n.d.  3-A n.d. 3-B n.d.  3-C 8.0-8.9  3-D ≥9.0  4-A n.d.  4-B ≥9.0  5-A n.d.  5-B ≥9.0 6-A n.d.  6-B ≥9.0  7-A n.d.  7-B ≥9.0  7-C n.d.  8-A n.d.  8-B ≥9.0  97.0-7.9 10-1 n.d. 10-2 8.0-8.9 10-3 ≥9.0 10-4 n.d. 10-5 n.d. 10-67.0-7.9 10-7 7.0-7.9 10-8 n.d. 10-9 8.0-8.9 10-10 8.0-8.9 10-11 7.0-7.910-12 8.0-8.9 11-1 8.0-8.9 11-2 7.0-7.9 11-3 8.0-8.9 11-4 8.0-8.9 11-5n.d. 11-6 8.0-8.9 11-7 8.0-8.9 11-8 7.0-7.9 11-9 7.0-7.9 11-10 n.d.11-11 8.0-8.9 11-12 n.d. 11-13 ≥9.0 11-14 n.d. 11-15 7.0-7.9 12-18.0-8.9 12-2 8.0-8.9 12-3 8.0-8.9 12-4 ≥9.0 12-5 ≥9.0 12-6 ≥9.0 12-7≥9.0 12-8 ≥9.0 12-9 ≥9.0 12-10 8.0-8.9 12-11 ≥9.0 12-12 8.0-8.9 12-13≥9.0 12-14 7.0-7.9 12-15 8.0-8.9 12-16 ≥9.0 12-17 8.0-8.9 12-18 8.0-8.912-19 7.0-7.9 12-20 8.0-8.9 12-21 ≥9.0 12-22 ≥9.0 12-23 8.0-8.9 12-247.0-7.9 12-25 7.0-7.9 12-26 8.0-8.9 12-27 ≥9.0 13-1 8.0-8.9 13-2 n.d.13-3 7.0-7.9 13-4 n.d. 13-5 7.0-7.9 13-6 7.0-7.9 13-7 7.0-7.9 13-87.0-7.9 14 8.0-8.9 15-1 7.0-7.9 15-2 8.0-8.9 15-3 8.0-8.9 15-4 8.0-8.915-5 ≥9.0 15-6 7.0-7.9 15-7 8.0-8.9 15-8 8.0-8.9 15-9 8.0-8.9 15-108.0-8.9 15-11 8.0-8.9 15-12 7.0-7.9 15-13 8.0-8.9 15-14 8.0-8.9 15-158.0-8.9 15-16 8.0-8.9 15-17 7.0-7.9 15-18 n.d. 15-19 7.0-7.9 15-208.0-8.9 15-21 ≥9.0 15-22 8.0-8.9 15-23 7.0-7.9 15-24 8.0-8.9 15-25 ≥9.015-26 ≥9.0 15-27 ≥9.0 15-28 ≥9.0 15-29 n.d. 15-30 ≥9.0 15-31 8.0-8.915-32 8.0-8.9 15-33 ≥9.0 15-34 8.0-8.9 15-35 ≥9.0 15-36 8.0-8.9 15-378.0-8.9 15-38 8.0-8.9 15-39 7.0-7.9 15-40 8.0-8.9 15-41 n.d. 15-42 ≥9.015-43 n.d. 15-44 8.0-8.9 15-45 n.d. 15-46 ≥9.0 15-47 n.d. 15-48 ≥9.015-49 n.d. 15-50 7.0-7.9 15-51 n.d. 15-52 n.d. 15-53 8.0-8.9 15-54 n.d.15-55 7.0-7.9 15-56 8.0-8.9 15-57 ≥9.0 15-58 n.d. 15-59 8.0-8.9 15-60≥9.0 15-61 ≥9.0 15-62 n.d. 15-63 ≥9.0 15-64 n.d. 15-65 7.0-7.9 15-66n.d. 15-67 ≥9.0 15-68 n.d. 15-69 7.0-7.9 15-70 8.0-8.9 15-71 8.0-8.915-72 7.0-7.9 15-73 7.0-7.9 15-74 7.0-7.9 15-75 8.0-8.9 15-76 8.0-8.915-77 7.0-7.9 15-77 8.0-8.9 15-79 ≥9.0 15-80 ≥9.0 15-81 7.0-7.9 15-828.0-8.9 15-83 ≥9.0 15-84 ≥9.0 15-85 n.d. 15-86 ≥9.0 15-87 n.d. 15-88n.d. 15-89 ≥9.0 15-90 ≥9.0 15-91 7.0-7.9 15-92 7.0-7.9 15-93 7.0-7.915-94 7.0-7.9 15-95 8.0-8.9 15-96 ≥9.0 15-97 n.d. 15-98 n.d. 15-99 n.d.15-100 8.0-8.9 15-101 7.0-7.9 15-102 ≥9.0 15-103 n.d. 15-104 n.d. 15-105n.d. 15-106 8.0-8.9 15-107 n.d. 15-108 7.0-7.9 15-109 8.0-8.9 15-1108.0-8.9 15-111 ≥9.0 15-112 8.0-8.9 15-113 7.0-7.9 16-1 ≥9.0 16-2 7.0-7.916-3 8.0-8.9 16-4 8.0-8.9 16-5 7.0-7.9 16-6 8.0-8.9 17-A ≥9.0 17-B n.d.18-1 n.d. 18-2 ≥9.0 18-3 ≥9.0 18-4 n.d. 18-5 n.d. 18-6 n.d. 18-7 ≥9.018-8 ≥9.0 18-9 ≥9.0 18-10 ≥9.0 18-11 ≥9.0 18-12 ≥9.0 18-13 ≥9.0 18-14≥9.0 18-15 ≥9.0 18-16 ≥9.0 18-17 ≥9.0 18-18 n.d. 18-19 ≥9.0 18-20 n.d.18-21 n.d. 18-22 n.d. 18-23 ≥9.0 18-24 n.d. 18-25 n.d. 18-26 n.d. 18-27≥9.0 18-28 n.d. 18-29 n.d. 18-30 n.d. 18-31 ≥9.0 18-32 ≥9.0 18-33 n.d.18-34 ≥9.0 18-35 ≥9.0 18-36 n.d. 18-37 ≥9.0 18-38 ≥9.0 18-39 ≥9.0 18-40≥9.0 18-41 ≥9.0 18-42 ≥9.0 18-43 ≥9.0 18-44 ≥9.0 18-45 ≥9.0 18-46 ≥9.018-47 ≥9.0 18-48 8.0-8.9 18-49 8.0-8.9 18-50 ≥9.0 19-1 ≥9.0 19-2 n.d.19-3 n.d. 19-4 n.d. 19-5 n.d. 19-6 ≥9.0 19-7 n.d. 19-8 n.d. 19-9 n.d.19-10 n.d. 19-11 n.d. 19-12 ≥9.0 19-13 n.d. 19-14 n.d. 19-15 n.d. 19-16n.d. 19-17 ≥9.0 19-18 ≥9.0 19-19 ≥9.0 19-20 ≥9.0 19-21 ≥9.0 19-22 n.d.20-1 ≥9.0 20-2 ≥9.0 20-3 ≥9.0 20-4 ≥9.0 20-5 ≥9.0 20-6 ≥9.0 20-7 ≥9.020-8 ≥9.0 20-9 8.0-8.9 21-1 ≥9.0 21-2 ≥9.0 22 ≥9.0 23-1 ≥9.0 23-2 ≥9.023-3 ≥9.0 23-4 ≥9.0 23-5 n.d. 23-6 n.d. 23-7 n.d. 23-8 ≥9.0 24 ≥9.0 25-17.0-7.9 25-2 8.0-8.9 25-3 ≥9.0 n.d. = not determined

Assay 2 Pharmacodynamic (PD) Assay for ACE and NEP Activity inAnesthetized Rats

Male, Sprague Dawley, normotensive rats are anesthetized with 120 mg/kg(i.p.) of inactin. Once anesthetized, the jugular vein, carotid artery(PE 50 tubing) and bladder (flared PE 50 tubing) catheters arecannulated and a tracheotomy is performed (Teflon Needle, size 14 gauge)to facilitate spontaneous respiration. The animals are then allowed a 60minute stabilization period and kept continuously infused with 5 mL/kg/hof saline (0.9%) throughout, to keep them hydrated and ensure urineproduction. Body temperature is maintained throughout the experiment byuse of a heating pad. At the end of the 60 minute stabilization period,the animals are dosed intravenously (i.v.) with two doses of AngI (1.0μg/kg, for ACE inhibitor activity) at 15 minutes apart. At 15 minutespost-second dose of AngI, the animals are treated with vehicle or testcompound. Five minutes later, the animals are additionally treated witha bolus i.v. injection of atrial natriuretic peptide (ANP; 30 μg/kg).Urine collection (into pre-weighted eppendorf tubes) is startedimmediately after the ANP treatment and continued for 60 minutes. At 30and 60 minutes into urine collection, the animals are re-challenged withAngI. Blood pressure measurements are done using the Notocord system(Kalamazoo, Mich.). Urine samples are frozen at −20° C. until used forthe cGMP assay. Urine cGMP concentrations are determined by EnzymeImmuno Assay using a commercial kit (Assay Designs, Ann Arbor, Mich.,Cat. No. 901-013). Urine volume is determined gravimetrically. UrinarycGMP output is calculated as the product of urine output and urine cGMPconcentration. ACE inhibition is assessed by quantifying the %inhibition of pressor response to AngI. NEP inhibition is assessed byquantifying the potentiation of ANP-induced elevation in urinary cGMPoutput.

Assay 3 In Vivo Evaluation of Antihypertensive Effects in the ConsciousSHR Model of Hypertension

Spontaneously hypertensive rats (SHR, 14-20 weeks of age) are allowed aminimum of 48 hours acclimation upon arrival at the testing site withfree access to food and water. For blood pressure recording, theseanimals are surgically implanted with small rodent radiotransmitters(telemetry unit; DSI Models TA11PA-C40 or C50-PXT, Data Science Inc.,USA). The tip of the catheter connected to the transmitter is insertedinto the descending aorta above the iliac bifurcation and secured inplace with tissue adhesive. The transmitter is kept intraperitoneallyand secured to the abdominal wall while closing of the abdominalincision with a non-absorbable suture. The outer skin is closed withsuture and staples. The animals are allowed to recover with appropriatepost operative care. On the day of the experiment, the animals in theircages are placed on top of the telemetry receiver units to acclimate tothe testing environment and baseline recording. After at least of 2hours baseline measurement is taken, the animals are then dosed withvehicle or test compound and followed out to 24 hours post-dose bloodpressure measurement. Data is recorded continuously for the duration ofthe study using Notocord software (Kalamazoo, Mich.) and stored aselectronic digital signals. Parameters measured are blood pressure(systolic, diastolic and mean arterial pressure) and heart rate.

Assay 4 In Vivo Evaluation of Antihypertensive Effects in the ConsciousDOCA-Salt Rat Model of Hypertension

CD rats (male, adult, 200-300 grams, Charles River Laboratory, USA) areallowed a minimum of 48 hours acclimation upon arrival at the testingsite before they are placed on a high salt diet. One week after thestart of the high salt diet (8% in food or 1% NaCl in drinking water), adeoxycorticosterone acetate (DOCA) pellet (100 mg, 90 days release time,Innovative Research of America, Sarasota, Fla.) is implantedsubcutaneously and unilateral nephrectomy is performed. At this time,the animals are also surgically implanted with small rodentradiotransmitters for blood pressure measurement (see Assay 3 fordetails). The animals are allowed to recover with appropriate postoperative care. Study design, data recording, and parameters measured issimilar to that described for Assay 3.

Assay 5 In Vivo Evaluation of Antihypertensive Effects in the ConsciousDahl/SS Rat Model of Hypertension

Male, Dahl salt sensitive rats (Dahl/SS, 6-7 weeks of age from CharlesRiver Laboratory, USA) are allowed at least 48 hours of acclimation uponarrival at the testing site before they were placed on a 8% NaCl highsalt diet (TD.92012, Harlan, USA) then surgically implanted with smallrodent radiotransmitters for blood pressure measurement (see Assay 3 fordetails). The animals are allowed to recover with appropriate postoperative care. At approximately 4 to 5 weeks from the start of highsalt diet, these animals are expected to become hypertensive. Once thehypertension level is confirmed, these animals are used for the studywhile continued with the high salt diet to maintain their hypertensionlevel. Study design, data recording, and parameters measured is similarto that described in Assay 3.

While the present invention has been described with reference tospecific aspects or embodiments thereof, it will be understood by thoseof ordinary skilled in the art that various changes can be made orequivalents can be substituted without departing from the true spiritand scope of the invention. Additionally, to the extent permitted byapplicable patent statutes and regulations, all publications, patentsand patent applications cited herein are hereby incorporated byreference in their entirety to the same extent as if each document hadbeen individually incorporated by reference herein.

1-28. (canceled) 29:(2R,4R)-5-Biphenyl-4-yl-4-[(5-carboxymethyl-1H-pyrazole-3-carbonyl)amino]-2-hydroxy-pentanoicacid or a pharmaceutically acceptable salt thereof. 30:(2R,4R)-5-Biphenyl-4-yl-2-hydroxy-4-[(5-hydroxymethyl-1H-pyrazole-3-carbonyl)-amino]-pentanoicacid or a pharmaceutically acceptable salt thereof. 31:(2R,4R)-5-Biphenyl-4-yl-2-hydroxy-4-[(5-methoxymethyl-1H-pyrazole-3-carbonyl)-amino]-pentanoicacid or a pharmaceutically acceptable salt thereof. 32:(2R,4R)-5-Biphenyl-4-yl-4-{[5-(3-carbamoylpyrrolidine-1-carbonyl)-2H-pyrazole-3-carbonyl]-amino}-2-hydroxy-pentanoicacid or a pharmaceutically acceptable salt thereof. 33:(2R,4R)-5-Biphenyl-4-yl-2-hydroxy-4-{[5-(4-hydroxypiperidine-1-carbonyl)-2H-pyrazole-3-carbonyl]-amino}-pentanoicacid or a pharmaceutically acceptable salt thereof. 34: A pharmaceuticalcomposition comprising the compound of any one of claims 29-33 and apharmaceutically acceptable carrier. 35: The pharmaceutical compositionof claim 34, further comprising an AT₁ receptor antagonist. 36: A methodfor therapeutically treating hypertension, heart failure, or renaldisease, comprising administering to a patient a therapeuticallyeffective amount of the compound of any one of claims 29-33.